Although classic can’t be granted as the snap doesn’t fit directly in one of the supported categories, there may still be some alternate solutions.
In regards to wanting users to specify folders/files:
- Perhaps using portals (XDG desktop portals) may suit your snap instead of
system-backupin your case as this enables users to select which files or folders to access.
Additionally, it looks like there was a recent dontnet-sdk snap release with a channel for 8.0 that may help fix some of the mentioned issues.