I’ve found an issue that effects a rust gui software, that manifests in kwin but not weston or mutter:
egui issue # 4259
The issue is that when egui resizes a window (not as a result of a configure), it triggers a configure for it’s original size.
Think destroying a currently attached wl_buffer triggers a xdg_toplevel configure, in egui this occurs before a new (resized) wl_buffer is attached resulting in a configure for the original size.
This configure isn’t sent in the case of weston and gnome.
This may be too technical for kde discuss.