What APG should add is an option to change the order in which things are processed. Now first everything is detected and at rendering time the fusion is done. The new option should be to first fuse a stack and then start detection and then later rendering.

This option can be set through general setting and copied to each new group when loaded.

This option will make life easier and faster, certainly for limited PC's, and will work best on panoramas without moving objects. Although if fusion is clever enough.....