Thanks for the hint. Indeed, I can check out existing code to get a more definite idea.
I have read that RegisterComponent is not needed in the constructor. But does that mean that actor components don’t need any further step? They will show up in the editor anyway?
Also, using SetupAttachment when creating components at runtime does work for me, too, in which case RegisterComponent seems to be redundant there, too. So I am still not sure, what I am doing really and just trying out to see what works.