After spending a few days testing, I’ve found that uploading a custom avatar that has multiple mesh parts forces a creation of a RooPart, which houses all the bone structure. Problem with this is it creates the RootPart below the mesh.
Here’s my rig, as you can see, the main body is under Armature, while the eyes are a separate mesh. Please note, the eyes are separate as to allow for them to have their own texture
When importing this, this is the result I get
This is incredibly infuriating, as I don’t want a RootPart, nor do I want that RootPart to be below the model. Moving this part causes the bones to move.
If I delete the eyes in blender, and then upload however, it uploads correctly
However, now it’s missing the eyes. Uploading the eyes seperatly would cause problems as it would be near impossible to position them correctly.
To me, the spine should always go under the mesh part that the armature is under. It makes no sense to randomly create a RootPart.