diff --git a/.github/workflows/regress.yml b/.github/workflows/regress.yml
index 0b42dd688..33fe52896 100644
--- a/.github/workflows/regress.yml
+++ b/.github/workflows/regress.yml
@@ -77,3 +77,11 @@ jobs:
           cd regress
           export ASAN_OPTIONS="abort_on_error=1:detect_leaks=0"
           ${{ matrix.make }}
+
+      - name: upload regress logs
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: regress-logs-${{ matrix.name }}
+          path: regress/logs/*.log
+          if-no-files-found: ignore
diff --git a/.gitignore b/.gitignore
index 46e3ad595..31ca7add0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,7 @@ configure
 core
 etc/
 fuzz/*-fuzzer
+regress/logs/
 tags
 tmux
 tmux.1.*
diff --git a/regress/Makefile b/regress/Makefile
index c354a8187..6370c77c9 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -1,22 +1,30 @@
 TESTS!= echo *.sh
+LOGDIR=logs
 
-.PHONY: all $(TESTS)
-.NOTPARALLEL: all $(TESTS)
+.PHONY: all
+.NOTPARALLEL: all
 
 all:
-	@failed=0; failures=; \
+	@mkdir -p "$(LOGDIR)"; \
+	rm -f "$(LOGDIR)"/*.log; \
+	failed=0; failures=; \
 	for test in $(TESTS); do \
+		base=$${test##*/}; \
+		log="$(LOGDIR)/$${base%.sh}.log"; \
+		rm -f "$$log"; \
 		printf '%-40s ' "$$test"; \
 		start=$$(date +%s); \
 		ASAN_OPTIONS="abort_on_error=1:detect_leaks=0:$$ASAN_OPTIONS"; \
 		env -i LC_CTYPE=C.UTF-8 ASAN_OPTIONS="$$ASAN_OPTIONS" \
-		    sh "$$test" >/dev/null 2>&1; \
+		    sh -x "$$test" >"$$log" 2>&1; \
 		if [ $$? -eq 0 ]; then \
 			end=$$(date +%s); \
+			rm -f "$$log"; \
 			echo "PASS ($$((end - start))s)"; \
 		else \
 			end=$$(date +%s); \
 			echo "FAIL ($$((end - start))s)"; \
+			echo " log: $$log"; \
 			failed=1; \
 			failures="$$failures $$test"; \
 		fi; \
@@ -28,9 +36,7 @@ all:
 		for test in $$failures; do \
 			echo " $$test"; \
 		done; \
+	else \
+		rmdir "$(LOGDIR)" 2>/dev/null || true; \
 	fi; \
 	exit $$failed
-
-$(TESTS):
-	sh $@
-	sleep 1
diff --git a/regress/choose-buffer.sh b/regress/choose-buffer.sh
index 7d689f523..a10d161eb 100644
--- a/regress/choose-buffer.sh
+++ b/regress/choose-buffer.sh
@@ -17,18 +17,23 @@ PATH=/bin:/usr/bin
 TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest -f/dev/null"
-TMUX2="$TEST_TMUX -Ltest2 -f/dev/null"
+TMP=$(mktemp -d) || exit 1
+TMUX_TMPDIR="$TMP"
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+TMUX2="$TEST_TMUX -Ltest2$$ -f/dev/null"
 
 cleanup()
 {
 	$TMUX kill-server 2>/dev/null
 	$TMUX2 kill-server 2>/dev/null
+	rm -rf "$TMP"
 }
+trap cleanup EXIT
+
 fail()
 {
-	echo "$1"
-	cleanup
+	echo "$1" >&2
 	exit 1
 }
 
@@ -46,16 +51,33 @@ wait_for()
 {
 	i=0
 	while [ "$i" -lt 50 ]; do
-		if capture | grep -q "$1"; then
-			sleep 0.5
+		CAPTURED=$(capture)
+		if echo "$CAPTURED" | grep -q "$1"; then
 			return 0
 		fi
-		sleep 0.5
+		sleep 0.2
 		i=$((i + 1))
 	done
 	fail "timed out waiting for '$1'"
 }
 
+# wait_count $marker $n
+#
+# Wait (up to ~10s) until exactly $n rendered lines contain $marker. The
+# matching capture is left in CAPTURED.
+wait_count()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CAPTURED=$(capture)
+		c=$(echo "$CAPTURED" | grep -c "$1")
+		[ "$c" -eq "$2" ] && return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	fail "timed out waiting for $2 lines of '$1' (have $c)"
+}
+
 # wait_buffers $n
 #
 # Wait (up to ~10s) until the test server has exactly $n paste buffers.
@@ -86,8 +108,30 @@ wait_clients()
 	return 1
 }
 
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
+# wait_mode $target $state
+#
+# Wait (up to ~10s) until a pane enters or leaves mode.
+wait_mode()
+{
+	t=$1
+	want=$2
+
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($TMUX display-message -p -t "$t" '#{pane_in_mode}' \
+		    2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	fail "pane $t mode state is $got, expected $want"
+}
+
+exit_mode()
+{
+	$TMUX send-keys -t aaa:0 "$@" || fail "send-keys $* failed"
+	wait_mode aaa:0 0
+}
 
 $TMUX new-session -d -s aaa -x 80 -y 24 || exit 1
 
@@ -100,57 +144,57 @@ $TMUX set-buffer -b bufz "other buffer" || exit 1
 
 # --- filter by buffer name ---------------------------------------------------
 $TMUX choose-buffer -t aaa:0 -F 'B1' -f '#{==:#{buffer_name},bufa}' || exit 1
-wait_for 'B1'
-out=$(capture)
+wait_count ': B1' 1
+out=$CAPTURED
 echo "$out" | grep -q 'bufa: B1' || fail "bufa missing when it matches"
 echo "$out" | grep -q 'bufz: B1' && fail "bufz shown but does not match"
 [ "$(echo "$out" | grep -c ': B1')" -eq 1 ] || fail "expected 1 buffer"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter by buffer content ------------------------------------------------
 $TMUX choose-buffer -t aaa:0 -F 'B2' -f '#{m:*hello*,#{buffer_sample}}' || \
 	exit 1
-wait_for 'B2'
-out=$(capture)
+wait_count ': B2' 1
+out=$CAPTURED
 echo "$out" | grep -q 'bufa: B2' || fail "bufa missing when content matches"
 echo "$out" | grep -q 'bufz: B2' && fail "bufz shown but content not matched"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- no filter shows both buffers ---------------------------------------------
 $TMUX choose-buffer -t aaa:0 -F 'B3' || exit 1
-wait_for 'B3'
-out=$(capture)
+wait_count ': B3' 2
+out=$CAPTURED
 echo "$out" | grep -q 'bufa: B3' || fail "bufa missing with no filter"
 echo "$out" | grep -q 'bufz: B3' || fail "bufz missing with no filter"
 [ "$(echo "$out" | grep -c ': B3')" -eq 2 ] || fail "expected 2 buffers"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter matching nothing ---------------------------------------------------
 #
 # Everything is shown and the filter indicator reports no matches.
 $TMUX choose-buffer -t aaa:0 -F 'B4' -f '#{==:#{buffer_name},nosuch}' || \
 	exit 1
-wait_for 'B4'
-out=$(capture)
+wait_count ': B4' 2
+out=$CAPTURED
 echo "$out" | grep -q 'bufa: B4' || fail "bufa missing with no-match filter"
 echo "$out" | grep -q 'bufz: B4' || fail "bufz missing with no-match filter"
 echo "$out" | grep -q 'no matches' || fail "no matches indicator missing"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- sort orders ---------------------------------------------------------------
 #
 # By name bufa sorts first and -r reverses.
 $TMUX choose-buffer -t aaa:0 -F 'B5' -O name || exit 1
-wait_for 'B5'
-capture | grep ': B5' | head -1 | grep -q 'bufa: B5' || \
+wait_count ': B5' 2
+echo "$CAPTURED" | grep ': B5' | head -1 | grep -q 'bufa: B5' || \
 	fail "bufa not first with -O name"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 $TMUX choose-buffer -t aaa:0 -F 'B6' -O name -r || exit 1
-wait_for 'B6'
-capture | grep ': B6' | head -1 | grep -q 'bufz: B6' || \
+wait_count ': B6' 2
+echo "$CAPTURED" | grep ': B6' | head -1 | grep -q 'bufz: B6' || \
 	fail "bufz not first with -O name -r"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- d deletes the selected buffer --------------------------------------------
 #
@@ -161,16 +205,16 @@ $TMUX send-keys -t aaa:0 d
 wait_buffers 1
 $TMUX list-buffers -F '#{buffer_name}' | grep -q 'bufa' || \
 	fail "wrong buffer deleted"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- C-t tags all buffers and D deletes the tagged ------------------------------
 $TMUX set-buffer -b bufz "other buffer" || exit 1
 $TMUX set-buffer -b bufb "third buffer" || exit 1
 $TMUX choose-buffer -t aaa:0 -F 'G2' || exit 1
-wait_for ': G2'
+wait_count ': G2' 3
 $TMUX send-keys -t aaa:0 C-t D
 wait_buffers 0
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- Enter runs the default command (paste-buffer) ------------------------------
 #
@@ -178,22 +222,14 @@ $TMUX send-keys -t aaa:0 q
 # into the shell in the pane, where it appears on the screen.
 $TMUX set-buffer -b bufa "hello buffer" || exit 1
 $TMUX choose-buffer -t aaa:0 -F 'G3' || exit 1
-wait_for 'bufa: G3'
-$TMUX send-keys -t aaa:0 Enter
-i=0
-while [ "$i" -lt 50 ]; do
-	[ "$($TMUX display -p -t aaa:0 '#{pane_in_mode}')" = "0" ] && break
-	sleep 0.5
-	i=$((i + 1))
-done
-[ "$i" -lt 50 ] || fail "mode did not exit after Enter"
+wait_count ': G3' 1
+exit_mode Enter
 i=0
 while [ "$i" -lt 50 ]; do
 	$TMUX capture-pane -p -t aaa:0 | grep -q 'hello buffer' && break
-	sleep 0.5
+	sleep 0.2
 	i=$((i + 1))
 done
 [ "$i" -lt 50 ] || fail "buffer not pasted into pane"
 
-cleanup
 exit 0
diff --git a/regress/choose-client.sh b/regress/choose-client.sh
index 1e8423415..9031f86bd 100644
--- a/regress/choose-client.sh
+++ b/regress/choose-client.sh
@@ -16,18 +16,23 @@ PATH=/bin:/usr/bin
 TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest -f/dev/null"
-TMUX2="$TEST_TMUX -Ltest2 -f/dev/null"
+TMP=$(mktemp -d) || exit 1
+TMUX_TMPDIR="$TMP"
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+TMUX2="$TEST_TMUX -Ltest2$$ -f/dev/null"
 
 cleanup()
 {
 	$TMUX kill-server 2>/dev/null
 	$TMUX2 kill-server 2>/dev/null
+	rm -rf "$TMP"
 }
+trap cleanup EXIT
+
 fail()
 {
-	echo "$1"
-	cleanup
+	echo "$1" >&2
 	exit 1
 }
 
@@ -45,16 +50,33 @@ wait_for()
 {
 	i=0
 	while [ "$i" -lt 50 ]; do
-		if capture | grep -q "$1"; then
-			sleep 0.5
+		CAPTURED=$(capture)
+		if echo "$CAPTURED" | grep -q "$1"; then
 			return 0
 		fi
-		sleep 0.5
+		sleep 0.2
 		i=$((i + 1))
 	done
 	fail "timed out waiting for '$1'"
 }
 
+# wait_count $marker $n
+#
+# Wait (up to ~10s) until exactly $n rendered lines contain $marker. The
+# matching capture is left in CAPTURED.
+wait_count()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CAPTURED=$(capture)
+		c=$(echo "$CAPTURED" | grep -c "$1")
+		[ "$c" -eq "$2" ] && return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	fail "timed out waiting for $2 lines of '$1' (have $c)"
+}
+
 # wait_clients $n
 #
 # Wait (up to ~10s) until the test server has exactly $n clients attached.
@@ -70,8 +92,30 @@ wait_clients()
 	return 1
 }
 
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
+# wait_mode $target $state
+#
+# Wait (up to ~10s) until a pane enters or leaves mode.
+wait_mode()
+{
+	t=$1
+	want=$2
+
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($TMUX display-message -p -t "$t" '#{pane_in_mode}' \
+		    2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	fail "pane $t mode state is $got, expected $want"
+}
+
+exit_mode()
+{
+	$TMUX send-keys -t aaa:0 "$@" || fail "send-keys $* failed"
+	wait_mode aaa:0 0
+}
 
 # One client attached to each of two sessions; the mode is displayed on the
 # client attached to aaa (in window 0 of the outer server) and the filters
@@ -86,43 +130,43 @@ wait_clients 2 || fail "expected two clients attached to test server"
 # --- filter keeping only the aaa client -------------------------------------
 $TMUX choose-client -t aaa:0 -F 'C1=#{client_session}' \
 	-f '#{==:#{client_session},aaa}' || exit 1
-wait_for 'C1='
-out=$(capture)
+wait_count 'C1=' 1
+out=$CAPTURED
 echo "$out" | grep -q 'C1=aaa' || fail "aaa client missing when it matches"
 echo "$out" | grep -q 'C1=bbb' && fail "bbb client shown but does not match"
 [ "$(echo "$out" | grep -c 'C1=')" -eq 1 ] || fail "expected 1 client"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter keeping only the bbb client -------------------------------------
 $TMUX choose-client -t aaa:0 -F 'C2=#{client_session}' \
 	-f '#{==:#{client_session},bbb}' || exit 1
-wait_for 'C2='
-out=$(capture)
+wait_count 'C2=' 1
+out=$CAPTURED
 echo "$out" | grep -q 'C2=bbb' || fail "bbb client missing when it matches"
 echo "$out" | grep -q 'C2=aaa' && fail "aaa client shown but does not match"
 [ "$(echo "$out" | grep -c 'C2=')" -eq 1 ] || fail "expected 1 client"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- no filter shows both clients -------------------------------------------
 $TMUX choose-client -t aaa:0 -F 'C3=#{client_session}' || exit 1
-wait_for 'C3='
-out=$(capture)
+wait_count 'C3=' 2
+out=$CAPTURED
 echo "$out" | grep -q 'C3=aaa' || fail "aaa client missing with no filter"
 echo "$out" | grep -q 'C3=bbb' || fail "bbb client missing with no filter"
 [ "$(echo "$out" | grep -c 'C3=')" -eq 2 ] || fail "expected 2 clients"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter matching nothing ------------------------------------------------
 #
 # Everything is shown and the filter indicator reports no matches.
 $TMUX choose-client -t aaa:0 -F 'C4=#{client_session}' \
 	-f '#{==:#{client_session},nosuch}' || exit 1
-wait_for 'C4='
-out=$(capture)
+wait_count 'C4=' 2
+out=$CAPTURED
 echo "$out" | grep -q 'C4=aaa' || fail "aaa client missing with no-match filter"
 echo "$out" | grep -q 'C4=bbb' || fail "bbb client missing with no-match filter"
 echo "$out" | grep -q 'no matches' || fail "no matches indicator missing"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- Enter runs the default command (detach-client) --------------------------
 #
@@ -131,10 +175,10 @@ $TMUX send-keys -t aaa:0 q
 $TMUX choose-client -t aaa:0 -F 'G1=#{client_session}' \
 	-f '#{==:#{client_session},bbb}' || exit 1
 wait_for 'G1=bbb'
-$TMUX send-keys -t aaa:0 Enter
+$TMUX send-keys -t aaa:0 Enter || fail "send-keys Enter failed"
 wait_clients 1 || fail "bbb client did not detach"
+wait_mode aaa:0 0
 [ "$($TMUX list-clients -F '#{client_session}')" = "aaa" ] || \
 	fail "wrong client detached"
 
-cleanup
 exit 0
diff --git a/regress/choose-tree.sh b/regress/choose-tree.sh
index 15add9f3f..b34cc2bd2 100644
--- a/regress/choose-tree.sh
+++ b/regress/choose-tree.sh
@@ -24,18 +24,23 @@ PATH=/bin:/usr/bin
 TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest -f/dev/null"
-TMUX2="$TEST_TMUX -Ltest2 -f/dev/null"
+TMP=$(mktemp -d) || exit 1
+TMUX_TMPDIR="$TMP"
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+TMUX2="$TEST_TMUX -Ltest2$$ -f/dev/null"
 
 cleanup()
 {
 	$TMUX kill-server 2>/dev/null
 	$TMUX2 kill-server 2>/dev/null
+	rm -rf "$TMP"
 }
+trap cleanup EXIT
+
 fail()
 {
-	echo "$1"
-	cleanup
+	echo "$1" >&2
 	exit 1
 }
 
@@ -53,11 +58,11 @@ wait_for()
 {
 	i=0
 	while [ "$i" -lt 50 ]; do
-		if capture | grep -q "$1"; then
-			sleep 0.5
+		CAPTURED=$(capture)
+		if echo "$CAPTURED" | grep -q "$1"; then
 			return 0
 		fi
-		sleep 0.5
+		sleep 0.2
 		i=$((i + 1))
 	done
 	fail "timed out waiting for '$1'"
@@ -70,11 +75,13 @@ wait_count()
 {
 	i=0
 	while [ "$i" -lt 50 ]; do
-		[ "$(capture | grep -c "$1")" -eq "$2" ] && return 0
-		sleep 0.5
+		CAPTURED=$(capture)
+		c=$(echo "$CAPTURED" | grep -c "$1")
+		[ "$c" -eq "$2" ] && return 0
+		sleep 0.2
 		i=$((i + 1))
 	done
-	fail "timed out waiting for $2 lines of '$1' (have $(capture | grep -c "$1"))"
+	fail "timed out waiting for $2 lines of '$1' (have $c)"
 }
 
 # wait_clients $n
@@ -92,8 +99,30 @@ wait_clients()
 	return 1
 }
 
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
+# wait_mode $target $state
+#
+# Wait (up to ~10s) until a pane enters or leaves mode.
+wait_mode()
+{
+	t=$1
+	want=$2
+
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($TMUX display-message -p -t "$t" '#{pane_in_mode}' \
+		    2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	fail "pane $t mode state is $got, expected $want"
+}
+
+exit_mode()
+{
+	$TMUX send-keys -t aaa:0 "$@" || fail "send-keys $* failed"
+	wait_mode aaa:0 0
+}
 
 # Session zzz is created first, so it sorts first by index, and has a
 # two-pane window 0 and a single-pane window 1. Session aaa has one window
@@ -117,10 +146,10 @@ wait_clients 1 || fail "no client attached to test server"
 # (session, window, pane).
 $TMUX choose-tree -t aaa:0 -F 'F1' -f '#{==:#{session_name},aaa}' || exit 1
 wait_count 'F1' 3
-out=$(capture)
+out=$CAPTURED
 echo "$out" | grep -q 'aaa: F1' || fail "aaa missing when filter matches it"
 echo "$out" | grep -q 'zzz: F1' && fail "zzz shown but no pane matches"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter keeping only zzz ------------------------------------------------
 #
@@ -128,10 +157,10 @@ $TMUX send-keys -t aaa:0 q
 # disappear.
 $TMUX choose-tree -t aaa:0 -F 'F2' -f '#{==:#{session_name},zzz}' || exit 1
 wait_count 'F2' 6
-out=$(capture)
+out=$CAPTURED
 echo "$out" | grep -q 'zzz: F2' || fail "zzz missing when filter matches it"
 echo "$out" | grep -q 'aaa: F2' && fail "aaa shown but no pane matches"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter matching a single pane ------------------------------------------
 #
@@ -139,22 +168,22 @@ $TMUX send-keys -t aaa:0 q
 # and that pane; zzz:1 and all of aaa must disappear.
 $TMUX choose-tree -t aaa:0 -F 'F3' -f '#{==:#{pane_index},1}' || exit 1
 wait_count 'F3' 3
-out=$(capture)
+out=$CAPTURED
 echo "$out" | grep -q 'zzz: F3' || fail "zzz missing when its pane matches"
 echo "$out" | grep -q 'aaa: F3' && fail "aaa shown but no pane matches"
 echo "$out" | grep -q '1: F3' || fail "matching pane missing"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter matching nothing ------------------------------------------------
 #
 # Everything is shown and the filter indicator reports no matches.
 $TMUX choose-tree -t aaa:0 -F 'F4' -f '#{==:#{session_name},nosuch}' || exit 1
-wait_for 'F4'
-out=$(capture)
+wait_count 'F4' 9
+out=$CAPTURED
 echo "$out" | grep -q 'aaa: F4' || fail "aaa missing with no-match filter"
 echo "$out" | grep -q 'zzz: F4' || fail "zzz missing with no-match filter"
 echo "$out" | grep -q 'no matches' || fail "no matches indicator missing"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- -h with the tree pane as the only match --------------------------------
 #
@@ -163,29 +192,29 @@ $TMUX send-keys -t aaa:0 q
 $TMUX choose-tree -h -t aaa:0 -F 'F5' -f '#{==:#{session_name},aaa}' || \
 	exit 1
 wait_count 'F5' 2
-capture | grep -q 'aaa: F5' || fail "aaa missing with -h"
-$TMUX send-keys -t aaa:0 q
+echo "$CAPTURED" | grep -q 'aaa: F5' || fail "aaa missing with -h"
+exit_mode q
 
 # --- sort orders ------------------------------------------------------------
 #
 # By index zzz (created first) sorts first, by name aaa does, and -r reverses.
 $TMUX choose-tree -t aaa:0 -F 'F6' -O index || exit 1
-wait_for 'F6'
-capture | grep 'F6' | head -1 | grep -q 'zzz: F6' || \
+wait_count 'F6' 9
+echo "$CAPTURED" | grep 'F6' | head -1 | grep -q 'zzz: F6' || \
 	fail "zzz not first with -O index"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 $TMUX choose-tree -t aaa:0 -F 'F7' -O name || exit 1
-wait_for 'F7'
-capture | grep 'F7' | head -1 | grep -q 'aaa: F7' || \
+wait_count 'F7' 9
+echo "$CAPTURED" | grep 'F7' | head -1 | grep -q 'aaa: F7' || \
 	fail "aaa not first with -O name"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 $TMUX choose-tree -t aaa:0 -F 'F8' -O name -r || exit 1
-wait_for 'F8'
-capture | grep 'F8' | head -1 | grep -q 'zzz: F8' || \
+wait_count 'F8' 9
+echo "$CAPTURED" | grep 'F8' | head -1 | grep -q 'zzz: F8' || \
 	fail "zzz not first with -O name -r"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- collapse and expand with h and l -----------------------------------------
 #
@@ -193,41 +222,43 @@ $TMUX send-keys -t aaa:0 q
 # l expands it again.
 $TMUX choose-tree -t aaa:0 -F 'G1' -O index || exit 1
 wait_count 'G1' 9
-$TMUX send-keys -t aaa:0 g h
+$TMUX send-keys -t aaa:0 g h || fail "send-keys collapse failed"
 wait_count 'G1' 4
-$TMUX send-keys -t aaa:0 l
+$TMUX send-keys -t aaa:0 l || fail "send-keys expand failed"
 wait_count 'G1' 9
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- filter entered at the prompt with f, cleared with c ----------------------
 $TMUX choose-tree -t aaa:0 -F 'G2' -O index || exit 1
 wait_count 'G2' 9
-$TMUX send-keys -t aaa:0 f
-$TMUX send-keys -t aaa:0 -l '#{==:#{session_name},aaa}'
-$TMUX send-keys -t aaa:0 Enter
+$TMUX send-keys -t aaa:0 f || fail "send-keys f failed"
+$TMUX send-keys -t aaa:0 -l '#{==:#{session_name},aaa}' || \
+	fail "send-keys filter failed"
+$TMUX send-keys -t aaa:0 Enter || fail "send-keys Enter failed"
 wait_count 'G2' 3
-out=$(capture)
+out=$CAPTURED
 echo "$out" | grep -q 'aaa: G2' || fail "aaa missing with prompt filter"
 echo "$out" | grep -q 'zzz: G2' && fail "zzz shown with prompt filter"
-$TMUX send-keys -t aaa:0 c
+$TMUX send-keys -t aaa:0 c || fail "send-keys c failed"
 wait_count 'G2' 9
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
 # --- Enter runs the default command (switch-client) ----------------------------
 #
 # g selects session zzz and Enter switches the client to it.
 $TMUX choose-tree -t aaa:0 -F 'G3' -O index || exit 1
 wait_count 'G3' 9
-$TMUX send-keys -t aaa:0 g Enter
+$TMUX send-keys -t aaa:0 g Enter || fail "send-keys Enter failed"
 i=0
 while [ "$i" -lt 50 ]; do
 	[ "$($TMUX list-clients -F '#{client_session}')" = "zzz" ] && break
-	sleep 0.5
+	sleep 0.2
 	i=$((i + 1))
 done
 [ "$i" -lt 50 ] || fail "client did not switch to zzz"
 $TMUX switch-client -c "$($TMUX list-clients -F '#{client_name}')" -t aaa || \
 	exit 1
+wait_mode aaa:0 0
 
 # --- x kills the current item after confirmation -------------------------------
 #
@@ -235,13 +266,12 @@ $TMUX switch-client -c "$($TMUX list-clients -F '#{client_name}')" -t aaa || \
 # kills it, leaving zzz with one window and the tree with seven lines.
 $TMUX choose-tree -t aaa:0 -F 'G4' -O index || exit 1
 wait_count 'G4' 9
-$TMUX send-keys -t aaa:0 g j j j j x
+$TMUX send-keys -t aaa:0 g j j j j x || fail "send-keys x failed"
 wait_for 'Kill window 1'
-$TMUX send-keys -t aaa:0 y
+$TMUX send-keys -t aaa:0 y || fail "send-keys y failed"
 wait_count 'G4' 7
 [ "$($TMUX list-windows -t zzz -F x | grep -c x)" -eq 1 ] || \
 	fail "window 1 of zzz not killed"
-$TMUX send-keys -t aaa:0 q
+exit_mode q
 
-cleanup
 exit 0