Does JME3 attach a unique ID to every element of a scene?

I have tested today on Ubuntu 24.04. Yes, it works on Linux, I can add my own controls to a spatial. Maybe I didn’t understood how the controls should work. I thought I should see in the SceneComposer fields with primitive data-types by my controls. But I don’t see any fields in the SceneComposer-window. Is it normal? Are they oriented on lazy-init for later initialization from the code?