ImGui was very fun to use but ultimately, it's very intensive for what it is. It showed 3 panes and sat at 20% CPU usage on my 13700F. I'm not sure if my code was just bad or if this is how ImGui is.
Layers are now added AFTER UiManager is initialized and the instance is set.
TryCreateUi no longer automatically starts the UI thread, for you to add layers & do any custom ImGui setup before starting the thread.