[@Partisan] Thanks for spelling it out. It helps me to hear grueling pain-points since it's the only taste I get.

As Ellri said, earlier in this thread I proposed an idea for implementing a special post shared between GMs/co-GMs as the "0th" post for each tab with its own revision history.

In the meantime, I might be able to think of a quick hack that at least frees you from round-tripping through the PM system. Might be most sensible to hack a revision system onto the post system at large (for all users) and the let GMs toggle on a "co-GMs can edit my OPs" switch.