I'm testing Phriction as collaborative area. "Subscribers" is useful because I can notify people about changes to a certain page and also because I can use the same field to control access to it, by using the Subscribers policy.
I would like to notify and inherit access for an entire subtree rather than just a single page. In particular, it's weird that access policies themselves (view/edit) would inherit from the page object but not the subscribers that control the policy.
If I could inherit subscribers, I'd be able to use the wiki as a way to keep everyone (who is already subscribed) updated without requiring active participation from them to subscribe to each new page. It would also decrease sources of errors because subscribers are already prefilled with sensible values so people are less tempted to pick incorrect ones instead.
(My use case for the access control stuff is to have a subtree in the wiki that pertains to just matters of our organization's Board. Both board members and regular organization members would benefit from being notified about every change in the subtrees they're subscribed to.)