We definitely need Coventry on a big board. If anything, putting a suspected troll into Coventry while we monitor their behavior helps quite a bit.
Also, we have had instances where we need to make a person's entire history go away; it is rare, but for legal reasons the member needed to have all of his posts removed. There is no way to do a massive soft delete on all posts without going directly to the database (at least when I did this back with XF 1.1), plus, a member with 1,000 posts may have, for instance, a dozen deleted posts out of 988 good ones, and if we soft delete, then later undelete the posts, we've then undeleted those dozen bad ones along with all of the good ones. Coventry preserves that.
I wonder, though...would it be that hard to accomplish with user permissions? If we had a new permission, such as "Member's posts visible to others", and could apply "Revoke" to it, that would be perfect. It would also open it up so I could add this to the warning system--we could issue a zero-point no-message warning just to capture some "history" on the user's account.
Wasn't this a suggestion at one point? I did a search but don't see anything.