Didn’t read your post.
Just chiming in to tell you that anything “spinning” at elevated speeds should be done via a material and not with acrually making the item rotate.
This engine includes motion blur, and motion blur is automatically applied / looks horrible on anything rotating.
The content examples have samples for car wheels you can refer to.
The item vertex can still rotate. But applying a controlled material function gives you 100% better results 100% of the time.
As far as the rest.
For anything mechanical there’s really little to no reason to use a skeletal mesh.
Which involves also having an animation blueprint.
It’s much more performant to attach and rotate static meshes around as separate parts. Even if it is 1 extra draw call.