Not sure why my comment wasn't acknowledged, but like I said, the difference is that since live is illegal in the UK, of course it will be very rare to see snakes who only eat live. If BP's are truly only started on f/t from the egg, then of course it'll be very easy to keep all snakes in the UK on f/t. It's unlike here, where ball pythons are almost always started on live, and some kept on live for years of their life, since many breeders also breed feeders and they don't bother switching them over when they can just offer live food from their rack- that's what makes it hard to switch, and that's why you'll find many more snakes who are impossible to switch here and not there.
People from the UK can say all they want: "I've never seen a snake only eat live". I mean... of course! You haven't been in the hobby in the states. Lol
Though I also believe Bogertophis that there are probably some people feeding their snakes live underground.