When pushing a block vertically, go to the left side of the block while it's moving and try walking past the block. You can't (until the block stops moving). I think this happens from other directions as well.
If a test quest is necessary, this one will do.
Here's another (diagonal movement off only, I think, and I hope I can explain this one well enough): If pushing a block from the left (from the top half of the tile), then moving around the top 1.5 tiles to the right (so the block stops a half tile to the right of where Link is) and pushing down before the block stops, Link can walk partway through the block (if a damage combo is present where the block is moving, it can damage Link too).
Minor issues, but I thought they should be brought up. Neither are new to RC1.