diff --git a/imgui.h b/imgui.h
index e0bea0f51..d62f56fa8 100644
--- a/imgui.h
+++ b/imgui.h
@@ -3521,7 +3521,7 @@ struct ImFontAtlas
     IMGUI_API void              RemoveFont(ImFont* font);
 
     IMGUI_API void              Clear();                    // Clear everything (input fonts, output glyphs/textures)
-    IMGUI_API void              ClearCache();               // Clear cached glyphs and textures.
+    IMGUI_API void              ClearCache();               // Clear cached glyphs and textures. Invalidates all AddCustomRectXXX return values.
 
     // As we are transitioning toward a new font system, we expect to obsolete those soon:
     IMGUI_API void              ClearInputData();           // [OBSOLETE] Clear input data (all ImFontConfig structures including sizes, TTF data, glyph ranges, etc.) = all the data used to build the texture and fonts.
@@ -3571,7 +3571,7 @@ struct ImFontAtlas
     // You can request your rectangles to be mapped as font glyph (given a font + Unicode point),
     // so you can render e.g. custom colorful icons and use them as regular glyphs.
     // - Since 1.92.X, packing is done immediately in the function call. Returns >= on success, <0 on error.
-    // - You can render your pixels into the texture right after calling the AddCustomRectXXX functions, without waiting for the Build() call.
+    // - You can render your pixels into the texture right after calling the AddCustomRectXXX() functions.
     // - If your backend supports ImGuiBackendFlags_RendererHasTextures:
     //   Texture may be resized, so you cannot cache UV coordinates: always use CalcCustomRectUV().
     // - If you render colored output into your AddCustomRectRegular() rectangle: set 'atlas->TexPixelsUseColors = true'
@@ -3579,7 +3579,10 @@ struct ImFontAtlas
     // - Read docs/FONTS.md for more details about using colorful icons.
     // - Note: this API may be redesigned later in order to support multi-monitor varying DPI settings.
     IMGUI_API int               AddCustomRectRegular(int width, int height);
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     IMGUI_API int               AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int width, int height, float advance_x, const ImVec2& offset = ImVec2(0, 0));
+    IMGUI_API int               AddCustomRectFontGlyphForSize(ImFont* font, float font_size, ImWchar codepoint, int width, int height, float advance_x, const ImVec2& offset = ImVec2(0, 0));
+#endif
     IMGUI_API ImTextureRect*    GetCustomRectByIndex(int index);
     IMGUI_API void              CalcCustomRectUV(const ImTextureRect* rect, ImVec2* out_uv_min, ImVec2* out_uv_max) const;
 
@@ -3925,13 +3928,11 @@ namespace ImGui
     //static inline void  SetScrollPosHere()                    { SetScrollHere(); }                                                // OBSOLETED in 1.42
 }
 
-//-- OBSOLETED in 1.91.7 (from January 2025): ImFontAtlasCustomRect becomes ImTextureRect
-// - ImFontAtlasCustomRect::X            --> ImTextureRect::x
-// - ImFontAtlasCustomRect::Y            --> ImTextureRect::y
-// - ImFontAtlasCustomRect::Width        --> ImTextureRect::w
-// - ImFontAtlasCustomRect::Height       --> ImTextureRect::h
+//-- OBSOLETED in 1.92.x: ImFontAtlasCustomRect becomes ImTextureRect
+// - ImFontAtlasCustomRect::X,Y          --> ImTextureRect::x,y
+// - ImFontAtlasCustomRect::Width,Height --> ImTextureRect::w,h
 // - ImFontAtlasCustomRect::GlyphColored --> if you need to write to this, instead you can write to 'font->Glyphs.back()->Colored' after calling AddCustomRectFontGlyph()
-// We could make ImTextureRect an union to use old names, such 1) this would be confusing 2) the fix is easy 3) ImFontAtlasCustomRect was always a rather esoteric api.
+// We could make ImTextureRect an union to use old names, but 1) this would be confusing 2) the fix is easy 3) ImFontAtlasCustomRect was always a rather esoteric api.
 typedef ImTextureRect ImFontAtlasCustomRect;
 /*struct ImFontAtlasCustomRect
 {
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 11f78e8c5..2a0a300a7 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -3199,9 +3199,21 @@ int ImFontAtlas::AddCustomRectRegular(int width, int height)
     return r_id;
 }
 
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+// This API does not make sense anymore with scalable fonts.
+// - Prefer adding a font source (ImFontConfig) using a custom/procedural loader.
+// - You may use ImFontFlags_LockBakedSizes to limit an existing font to known baked sizes:
+//     ImFont* myfont = io.Fonts->AddFontFromFileTTF(....);
+//     myfont->GetFontBaked(16.0f);
+//     myfont->Flags |= ImFontFlags_LockBakedSizes;
+int ImFontAtlas::AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int width, int height, float advance_x, const ImVec2& offset)
+{
+    float font_size = font->Sources[0].SizePixels;
+    return AddCustomRectFontGlyphForSize(font, font_size, codepoint, width, height, advance_x, offset);
+}
 // FIXME: we automatically set glyph.Colored=true by default.
 // If you need to alter this, you can write 'font->Glyphs.back()->Colored' after calling AddCustomRectFontGlyph().
-int ImFontAtlas::AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int width, int height, float advance_x, const ImVec2& offset)
+int ImFontAtlas::AddCustomRectFontGlyphForSize(ImFont* font, float font_size, ImWchar codepoint, int width, int height, float advance_x, const ImVec2& offset)
 {
 #ifdef IMGUI_USE_WCHAR32
     IM_ASSERT(codepoint <= IM_UNICODE_CODEPOINT_MAX);
@@ -3209,7 +3221,9 @@ int ImFontAtlas::AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int wid
     IM_ASSERT(font != NULL);
     IM_ASSERT(width > 0 && width <= 0xFFFF);
     IM_ASSERT(height > 0 && height <= 0xFFFF);
-#if 0
+
+    ImFontBaked* baked = font->GetFontBaked(font_size);
+
     ImFontAtlasRectId r_id = ImFontAtlasPackAddRect(this, width, height);
     if (r_id < 0)
         return -1;
@@ -3217,8 +3231,8 @@ int ImFontAtlas::AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int wid
     if (RendererHasTextures)
         ImFontAtlasTextureBlockQueueUpload(this, TexData, r->x, r->y, r->w, r->h);
 
-    if (font->IsGlyphLoaded(codepoint))
-        ImFontAtlasBuildDiscardFontGlyph(this, font, (ImFontGlyph*)(void*)font->FindGlyph(codepoint));
+    if (baked->IsGlyphLoaded(codepoint))
+        ImFontAtlasBuildDiscardFontBakedGlyph(this, font, baked, (ImFontGlyph*)(void*)baked->FindGlyph(codepoint));
 
     ImFontGlyph glyph;
     glyph.Codepoint = codepoint;
@@ -3230,15 +3244,10 @@ int ImFontAtlas::AddCustomRectFontGlyph(ImFont* font, ImWchar codepoint, int wid
     glyph.Visible = true;
     glyph.Colored = true; // FIXME: Arbitrary
     glyph.PackId = r_id;
-    ImFontAtlasBuildAddFontGlyph(this, font, &font->Sources[0], &glyph);
+    ImFontAtlasBakedAddFontGlyph(this, baked, &font->Sources[0], &glyph);
     return r_id;
-#endif
-    // FIXME-BAKED: Need a design for AddCustomRectFontGlyph()
-    IM_UNUSED(codepoint);
-    IM_UNUSED(offset);
-    IM_UNUSED(advance_x);
-    return -1;
 }
+#endif // #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 
 ImTextureRect* ImFontAtlas::GetCustomRectByIndex(int idx)
 {