When stacking barriers 2+ high (As to make the block height as tall/taller than the player) and putting them in front of other barrier walls 2+ high, the barriers will flicker, creating a distracting jumble of blocks. This makes it very hard to create invisible mazes/ things with a high amount of barriers as it can get hard to tell where something is. The barriers also move as you change the way you are facing, only adding to the problem.