I noticed in the gateway manual that it is legal to use a 12x24 sheet, no more than 0.6in thick, and can be cut into smaller sections. Now, onto my question, is it legal to cut a 12x24 sheet of polycarbonate 0.6in thick into another 12x24 sheet that is 0.3in thick, and still use the other piece which was cut that is 0.3in thick too?
No, this would not be legal. The sheet you use cannot be cut into thinner pieces.
/Edit: To clarify, I’m assuming you a meant 0.06" thick piece. Anything larger than 0.0625" would be illegal.