Hey @acarl005, as an update, the review team had more of a discussion on the intended purpose of the system-backup interface and we backtracked on the what I have said before (see this update on the forum topic I linked before here).
Essentially, the discussion concluded that system-backup should really be used for system backups rather than general purpose use. Apologies for the confusion before.
In regards to the classic confinement request, I have had a look at some similar cases to do with file manager snaps (which ls-go would align with) requesting classic and we (reviewers and snap architect) came to the conclusion that file manager type snaps won’t be granted classic. For some added context here is a forum topic that discusses this: Classic confinement request: System G.
Again, sorry for the flip flopping on this.