Just found out about this plugin, its not directly related to what I’m trying to do, but it makes me think there might be a way to construct a spherical projection of an image as a layer through the python api and have brush strokes projected back onto the original image. Much like this plugin it would be kind of slow, but I haven’t made much progress in my mod yet and I still don’t feel very close to having a working solution.
Also I have yet to talk directly to the devs on their IRC channel