It seems that the UK government changed the rules for people transiting airside, and filling a PLF is no longer required. This change happened 2 weeks ago.
However, BA* and
VeriFLY still ask for the PLF
for airside transits (and also Timatic still shows the old rules). How long it will take to BA to "realize" that the rules are different now? I mean, It's not like these are rules for a different country...
*I received an email this morning were it was specified "If you’re connecting through the UK, you’ll still need to complete a passenger locator form separately"