Quite a few clan people these days walk around with their location turned off. In pents and AT, that can be a bit of an issue.
Grabbed your first pent when someone had grabbed 10 already and was reaching for the 11th...that's not cool. Or jumping into a room in AT that is already occupied.

You can of course ask in shouts, but not everyone reacts quick, some people miss things in the spam.

Showing everyone's location on /who, when that starts with "pentagram" or "abandoned town" would work.
Or, perhaps 2 new commands?

/pcount to show pc and amount of people in pents. Perhaps their location too. No names, if invisibility status is wanted.

And /atrooms to show what rooms are occupied. Would be great to see the rooms that have been occupied for the last 10 minutes, in case some people run multiple rooms.

I have my location on and in the last 4 days have had 3 people come into my AT room. 3 different people.

So to me that means most people do not check, they just go in.

Or, we could use the old-fashioned /shout command like we did for years before we could turn who on/off for clan members. I don't want to be seen. Unfortunately, I get targeted for the sins of the forefathers of the clan I'm in. If someone shouts asking if I'm penting and I don't answer, that's on me if they take the solve. It's not hard for someone to ask "anyone penting?" or "anyone in general AT?"