As a way of implementing something akin to XenForo's "Reply Bans" feature, but with slightly more control,
This is implemented in 4.1.0 Beta 2:
There is now a form where you can Allow/Block against specific users, for specific actions for permanent/temporary durations. If Block is used, the user's permissions are ignored, and they cannot perform the selected actions on that content. If Allow is used, the user's permissions are ignored, and they are allowed to perform the selected actions on that content anyway. If there are competing Allow and Block rules for the same user-action combination, the Block is used.
For pages:
- The form is part of the Protect tab. You may allow/block the Edit action.
This should allow pages which are collaboration protected, or have any other protection, to be editable by specified users.
For feeds:
- The form is part of the Protect tab. You may allow/block Adding entries to the feed.
This should allow feeds which have entry protection, to receive new entries from specified users.
For discussions:
- The form appears under the "Manage Reply Bans" link. You may allow/block Replies.
This should roughly emulate the reply-bans function.