Originally Posted by
KARFA
So I think what you quoted makes it clear it is 3 hours.
As you say, HKG comes to mind as an exception. Maybe JFK as you can bag drop in the afternoon for a late evening flight considering the large number of BA flights. But otherwise I can't think of any other for long haul. Very few outstations have manned/automated bag drops beyond 3 hours before the flight.
My reading of the BA information is that it states that airport desk check-in opens 3 hours before departure, it is the first sentence about online check-in and Bag Drop that I feel is open to misinterpretation.