OK, thanks for he comments.
Arrived at LGW Thu night around 1815. Followed sign to Premium Passport Control (at N. Terminal at far left) Greeted by a young gentlemen who read our printed receipts (no sign of barcode) and checked our names off a list. He then took us to the front and after a 2 minute wait we were shown to an officer. Couple of questions and my (3rd country) passport stamped and that was that. EU queue wasn’t terribly long but non-EU had 25 or so pax, and one officer to deal with them.
Following morning four of us went to TUI bag drop, which was confusing, Then approached young lady at Security and asked about Premium, not well signed posted. Got escorted to a short queue and was through in about 10 Minutes. Two of us had bags diverted to hand check, but lady there didn’t know why, and just told us to go ahead.
TUI flight out delayed over an hour due to problem with pitot tube. Arrived in rainstorm.