Heathrow T2, not too busy but very slow.
PRINT the required documents, the amount of people who didn't and then had to pay an over inflated fee at a nearby printer was unbelievable.
Documents requested:
1. Passport
2. RT-PCR certificate
3. Thailand Pass
4. Visa if required
Check in said the flight was full, but I have no idea. "Leg room seats" now come with an £80 additional charge (the ones by the exits - I've not be charged before, could be a misunderstanding).
ATM cost £2:50 to use once through security so get your GBP before hand.
Most eateries are open.
TLDR : Answer Summary
Traveling through Heathrow T2 can be slow, with a recommendation to print required documents in advance to avoid high fees for airport printing services. Essential documents include a passport, RT-PCR certificate, Thailand Pass, and visa if necessary. Additionally, airlines now charge for seat selection, including extra fees for 'leg room seats.' Travelers should be aware of ATM fees and prepare currency beforehand.