Oh geez. 🙁
I thought whitespace stripping was possible to do in Spine - did not notice the caveat. We wanted left some extra space in the source image so that our concept artist could paint over the character's raw assets without needing to get it re-rigged each time she needed to make a single part larger.
As you can see, the current skeleton is just a greyscale figure to help get proportions and such right. The idea is to then hand-off to a character artist who will paint in colors, details and a bump-map for lighting.
What's causing the white space stripping to play poorly with meshes?
Even more specifically - is this a "haven't yet fixed", "it can't be fixed" or "it could be, but won't be fixed" issue?
It seems liked this should just be a coordinate mapping issue, but I am still a novice in this area.