We have a "never" permission setting... why not an "always" one? Would be handy for setting up Super Admin/Super Moderator permissions across private nodes, etc. Put it over next to the "never" one with a similar warning.
As Brogan said, this would lead to impossible situations. The "Never" situation means that you can only end up with fewer permissions than you expect, rather than granting things you don't expect, which is potentially much worse.
Ugh.... I've got to work out the proper implementation now, too? I started to think that the last field could just be an always/never toggle, but that wouldn't necessarily work with nested usergroup permissions.
Bottom line... not sure. But practically speaking, it's a real pain to have to have to add global moderator permissions into private forums. Maybe there's a better way of accomplishing the same thing.