I just built my dome. This is sort of a Mod but isn't. It was an older model so I don't know if this has changed.
I didn't like the way the wheels mounted on the post tightened. When the bolt passed thru the post if I tightened the bolt to the point that I liked how tight the wall was I didn't like how tight the wheel was. So I added a washer & nylon lock nut inside the post. This way I could tighten the wall down & still keep the wheel nice.
Update: WARNING I forgot to add that if your are going to do this & use nylon lock nuts you need to make sure you turn the nut slowly. It was a long nut so on my first one I went fast with my ratchet. It generated heat which melted the nylon & it went into the threads & locked the nut to the bolt. It was locked so bad & couldn't get it off & had to cut the bolt.