I'm not sure if this is a known issue or not, but if I disable 'Inherit Scale' for some bones, they render fine in Spine, but upon importing into Godot, the transforms for those nodes are borked. If enabled, they are transformed as expected.
I have a few other things going on (like transform constraints assigned to a skin) that might be contributing, but I wanted to see if this is a known issue before troubleshooting further.