I share your concern Curious, but references to Paddington etc probably limit potential locations to about 10,000 possibilities.
The only way you're going to find out the exact address is to get an invite to a party, via membership.
Phoenix management have the job of weeding out any potentially malicious guests.
If my info is correct the move out of LG and Westminster was because landlords wanted to sell the properties. Not a lot LMP could do about that.
ER was a different matter, with problems with neighbours.
None of my business, but I believe the operation is all above board with a bona fide club established, with willing participants, with knowledge of the council and potential due payments to HMRC.
However the risk always remains that the landlord may wish to sell and therefore the maximum time guarantee would be set by the length of the lease and the termination clauses. I doubt if Phoenix want to purchase the property outright.
At least in the new place there are no neighbours to upset.
..and I agree, it's the best place yet.