Alright, this is much clearer - aside from a single outright "No" vote, everyone (so far) has voted for "Only in CPM".
Short of a very sudden change in that, it looks like that's the way forward - counts will be shown only for limited-count or zombie entrances during normal gameplay, but all entrances when in CPM. I notice the potential for this to obscure terrain near the entrance, so I'll either make it intermittent (appears for a sec, then disappears, etc) or semitransparent - probably the former.