if you build up to the height limit with scaffolding an interesting bug can be created. by standing to one side of the scaffolding and holding the build button, you can build a scaffolding platform going across like normal, however, if you try to add scaffolding onto any of these blocks, they will disappear and connected scaffolding will be left floating. 

sometimes, if at the right angle like in this image, it will spawn a scaffolding block next to the one that was deleted. repeating the process on this block will remove it however

breaking scaffolding blocks at the height limit in general does not cause them to fall either, they float.