That might be the problem as the material may discolour with the heat cycles/uv infra red too.
Lexan and plexiglass do have a technical support so might be worthwhile to drop them an email.
Thinking about this laterally, you can get plastic splashbacks/wall coverings in commercial kitchens, that stay smooth for cleaning and may cover the heat range that you need.
Might be worthwhile to look at PVC panels, if it doesn't need to be clea/see through. Used in a few bathrooms as it is cheaper than tiling and can be cheap way to make a wet room and seems not to get damaged by heat from lights left on for hours or students being careless.
That might be the problem as the material may discolour with the heat cycles/uv infra red too.
Lexan and plexiglass do have a technical support so might be worthwhile to drop them an email.
Thinking about this laterally, you can get plastic splashbacks/wall coverings in commercial kitchens, that stay smooth for cleaning and may cover the heat range that you need.