So tiny! And I've even put a unneeded courtesy block in there to make life easier. Movie of the solution: Spoiler: Movie
@richardfu_ It's required for the lift. Other configurations and B couldn't get on the lift. I am constraining myself with these size levels to also fit B's start location. During gameplay he may climb ontop. This is the same as for the 16x16x16 overall limit.
@Ricko Picture doesn't show correctly, but indeed, it works! Nice. It does handle a bit differently though, and....... unfinished rail.
@Ricko So, you need at least a dimenion of 3 in height to not have an unfinished rail, that also allows movement (using the floor to finish a rail). A horizontal rail will already require a dimension of 4 to allow movement. Ugh!
Rule of Mekorama: If it's too small, it's probably too tricky. How do you even come up with these ideas? You put a lot of blocks where B shouldn't walk on and hope for the best? Well, thanks for the trick!
@Chuckthulhu Actually this one was reasoned. Based on the theory of the Springboard Stairs trick. Spoiler Instead of stepping of stairs, the slider now makes B lower his body, making everything reachable from the block below the stone block in the corner.