Cool idea, but you do not need to use B on the level. Just wait for R bot get on the elevator and use the elevator to go R in win block.
@Ítalo is right but the intended path is fun...not so difficult but I add a star because I like the climber zappers,so cool!! Thanks for sharing and well done @caribou
Original idea but it had a huge shortcut and in general too random. Thanks! Spoiler: Shortcut It can be finished with zappers.