I found that if you read back on some people's threads that you can often find different hints about where they can be found. I've found a number of people that way but only connected to a couple, usually after they've found me. It can be quite startling to have someone who you only "know" semi-anonymously suddenly pop into 3 dimensions.
I do agree with the policy of discouraging posters from connecting IRL. For some, especially those in early days who really want to, they are also quite vulnerable. Trolls and other nasties are indeed a thing that the moderators I am sure are kept somewhat busy keeping at bay are also watching.
As far as keeping mentions of other sites from the board, this is underneath it all, a commercial enterprise. If we play in this sandbox we need to abide by the rules. I've posted from time to time on a couple of other sites and some who do are fairly obvious in their screen name or story when they are also here. I've gotten private messages on those forums which are basically a wave "hello".
Just my 2 cents.
On BD H52, W50 T27, M26 S21, D23 BD-9-Mar-16 D-15-Jan-18 Final-19-Apr-18 I am a storyteller. The story may do you no good. But a story is never for the listener. It is always for the one who tells