Is using a 2D magnetic board in tournament play legal? Is it okay to have a 2d magnetic chess set next to your score sheet? And as you play, you move along with the pieces. I like looking at a 2d board better because it's smaller and I'm used to playing on my computer. I look at the 2d board and then play on the 3d board. After I've made my move on the 3d board. THEN I move the pieces on the 2d board. Is there a rule against playing like this in tournament?
I'm pretty sure the rules of most serious tournaments prohibit the use of a second board for any reason, but I'm not sure if there are special provisions for people with disabilities and disadvantages.

As a player, I would be quite apprehensive towards playing someone who is using a second board, simply because it means I have to keep an eye out to ensure he is not cheating. I would certainly have a word with the arbiter if that situation were to occur.