What is the problem you are trying to solve?
Where a fragment is saved into GLOBAL and not in the single Site, “View usage” shows only what sites are using this fragment but is not possible to choose single pages that should have propagated edits.
What is your project about? (e. g. Intranet, Partner Portal, Enterprise Website, etc)
ALL
What is your proposed solution? (optional)
Could be perfect if Site names will become a “Tree root”, that expanded will show every child page that is using the fragment and a checkbox beside each one to specifically choose propagation criteria