Bot Paths Half height blocks

I wanted to create blocks that were positioned half as high as the ones above them. I found that B can only move forward over the blocks, but not sideways.

To create this effect I had to find something the blocks would fall down onto. Alas fences and pipes act as full height blocks - they have a gap above them! The only thing I found worked was the zapper.

Try my demo to see what I mean. Don't move the blocks themselves, just tap on them. You can move forward but not sideways, yet the height looks as if you can.