Not sure yet. The thing that actually drove it was that I didn't like seeing the redundancy in the stack traces when I was debugging. At first I played around with trimming them out of the stack trace but that ran in an issue - I couldn't figure out exactly how the indexing of stack frames was coordinated between emacs and lisp. Then it occurred to me that they didn't need to be there in the first place. So it's more of an aesthetic thing for now.

Alan