Don't Use

Spoiler: Do you mean...?

autopilot on right elevator and jump to the win lowering the elevator when B tries to go to the stairs?

I tried a more logic solution. I was able to use both balls, help R to cross right side but he doesn't go to the win, he gets blocked (hidden eye pressing up below the floor?).

It does not make much difference whether or not B pushes the lower ball. In either case, B reaches the win without too much trouble.

I wanted to rate this one higher, but the red herrings were pretty annoying because it took so long to set them up and try them. If the red herring is short enough sometimes people are ok with it, but if the red herring is too long it is usually frustrating. The solution isn't too difficult to pull off though.