Spoiler: Trick List - auto pilot (tap and move slider to redirect B) - low ceiling (B acts strangely with a low ceiling and may travel over blocks that B can't normally do) - maybe cancel tap due to low ceiling (tap some place on the level where B can't go to stop the move) Spoiler: Video Solution
Fun level. My start was different and shorter. I think your longer start is perhaps to ensure a perfectly upright P but i managed that without any help from B.
I skip your hard previous level Sorry Any way nice simple logic My first win (B drop the ball) by auto pilot and cancel tap used slider. B landed near the lift and got the ball