I flew yesterday from Heathrow to the US (not MCO; heading there later this week on a domestic US flight). I'm a dual citizen so have been able to travel between the UK (where I live) and US (where my family are) all through the last year and and a half. I just wanted to give a heads up that the
Virgin Atlantic check in zone yesterday at Heathrow was chaos.
I fly between the two countries 1-3 times a year (for the last 15 years), always arrive 2 hours early (I know 3 hours is often recommended for intl), and have never seen carnage like this. Virgin has you first queue at a documents check line to check your vaccine proof and test results (this was new since my last flight before the borders reopened; in the summer they just checked our test results at the counter), and then you get into the bag drop line for the counter and the usual passport verification/bag drop. And they just barely moved (while I was in the documents line I was watching the bag drop lines to see if they were moving....they were not. It was like watching snails). I ended up in the flight closures line for my check in (and luckily was pulled into it comparatively early as I was near the front and then that queue also ended up extending all the way back to the window).
It may have been worse because it was a Saturday (and the weekend before the US' Thanksgiving holiday), but just a heads up for everyone to make sure to give yourself plenty of time!
Testing wise, I've used Qured for the supervised lateral flow for both my trips out to the US (since that rule was introduced) and Project Screen for my return to the UK lateral flow (when it was needed) and day 2 test, and have had no problems with either (Project Screen also gave me a refund this summer because the return testing rules changed after purchase/pre-use).