I use ImGui for gui in a user-facing app that is "large-ish" (~500k LOC maybe). When removing items from lists etc I used to keep drawing non-removed items in the list so the user would not see a "glitch". But I realized it is not necessary. Just cut it short. The user can only take one action per frame from mouse click or button press etc. It's totally fine to render one frame a bit "strange" when someone deletes or adds to a list.

There is no problem in redrawing everything from state every frame. There is no problems in having "half frame be old state" - even at 30 fps it is not noticeable.

We use a separate update() and gui() path though. So all entities will get an update opportunity even if the gui is hidden. And state is kept in a config that is beautiful to use... Maybe the issues here comes from not having those parts.