How do you keep it from wobbling? I have a playseat too, and my frame moves a lot while I'm driving. I noticed last night that it almost lifts the bottom 2 braces that come out to the sides off of the ground when I'm turning with FF on.
Last night I was thinking about taking a large piece of plywood and bolting it to the bottom of those two side supports in hopes that it would prevent them from twisting so much. There is no way I could connect monitors to mine like you have done. They would flop all over the place.
In all honesty though you really don't notice the wheel moving while driving. The only reason I have started to notice it, is because I have my wheel base right underneath of a table, and the wheel moving around hits the bottom and kind of moves my monitors around a little.
You mod though does look really nice. It looks like you did a great job with it.