That’s not quite it - those are simply transform attachment relations and aren’t really making the secondary actor part of the first one. More like a child-parent relation in a 3D software. It wouldn’t let me edit the whole resulting object in the blueprint editor.
I’m leaning towards using a static method which creates the subobject components and passes the references in one go. It still ends up with some extra boilerplate in every actor class I’m going to add the functionality to - Instead of being able to spawn one component which would then bring everything it needs with it, all editable in the editor, I need to add the definitions of every component to the headers of the classes I include it to - but at least it lets me edit the components on the editor side of things.
I haven’t used Unity much, but IIRC you could nest prefabs with prefabs so adding a “component” with multiple subcomponents would be much simpler.
I’m not quite sure why components can’t have their own subcomponents or why actors can’t function as components of other actors, but my best guess is that it’s somehow related to how replication is handled.