I am not sure about the 3 exams for a Uk licence, but any pilot with a type on a multicrew aircraft that meet the conversion minimum ( sorry, cannot remember them but if needed i can find out) can take a single checkride and have his/hers licence issued with that type rating.
I fly LJ35, so converting would not do me any good, but anybody with 737/A320 type might benefit from it!
Good Luck!