Good info, Xelnath. :yes:
The simulated property is a good candidate for use.
But we're still supporting 5.4 for at least a few more months. (ie, let's let 5.5 stabilize a bit more)
That said, we are aware of certain things causing a rebuild of physics objects. This is the same reason why we don't support weighted collider shapes.
The Rigidbody2D setup is also up to the user. The different child colliders can share one parent Rigidbody, or they can each have one, or some combination in between.
Colliders without Rigidbodys are typically used/considered part of the "level geometry" and you wouldn't use rigidbodies on them unless they were destructible. So you never want that setup on your moving-around-all-the-time character. Same with child collider Transforms under rigidbodies, since box2D doesn't give each fixture a its own transform anyway. That's why you shouldn't move them. I guess that's where adding kinematic rigidbodies per GameObject with Colliders comes in.
I'll try to add some docs regarding Unity behavior but it'll be useful to hear the info straight from the horse's mouth (ie, it's a specific way you need to set it up in Unity, and Unity docs should cover it. This thread will do though)
