Chessington do use their excuse that can't go above 70ft or something (I'm not quite sure) but look at Alton Towers, they have a restriction that they can't go above the treeline which isn't very high but yet they pull off and create anything they want.
In a park like that the last thing you'd expect is a dive coaster (maybe a hypercoaster but that's not the point) but look, they've got a dive coaster and it has a drop longer than Baron 1898, Krake and Oblivion: The Black Hole.