Is there a way to bake entities without using a SubScene? (2022.3.21f - Entities 1.0.16)

[light sigil]

I'm experimenting some hydrid approaches to ECS and MonoBehaviour, and the traditional uGUI does not like being under a SubScene (EventSystem and GraphicRaycast doesn't work). However, it seems that the entities does not like not being under a SubScene.
What I want to do is just use the main scene in order to keep managed component references to GameObjects correct. However, this way, the entities aren't baked/created, so it's kind of a chicken and egg problem.

[dire pivot]

you don't need to put everything inside subscene

if you need some UI stuff in ECS world - just have a system that gets reference to your UI (or instantiates it)