maybites
commented
1 year ago not much I can do about this. It seams the Offline Render Feature the Python API exposes renders without transparency:
https://docs.blender.org/api/master/gpu.html#rendering-the-3d-view-into-a-texture
not sure if it's an issue or a limitation, but enabling transparent film makes the background go mid gray. if alpha could be somehow supported it would be crazy, but if not, at least having a plain black bg would probably be more correct.