DL Signs
Never go against the family
half inch acrylic? Wow, I use clear half inch as tops for our 4x8' lighted tables with cutting mats over it, and they've never warped at all. Takes a lot of pressure/ heat, or both to warp that. Starting to sound like whatever substrate you end up using will need to have better structural integrity, and probably be laminated on both sides to boot... I'd be thinking about aluminum as an option too, and lam both sides. The crazy issues we deal with...I have had 1/2" acrylic signs do the same thing with laminate glued to the face