Definitely a great Idea!
I looked into and tested different films.
There are a variety of quality. all labeled as "privacy"...even thin material on rolls.
With that comes a low to high of price.
As expected, the lowest rolls, were more a "window tinting", despite the promises, and the least expensive.
I couldnt recommend them at all.
The next kind was thicker, in sheets, and could be cut by scissors. It worked Kinda, but also wasnt clear. I would label these "Chinese 3M knockoffs" I know if I offered these, many people would be
The real stuff works, and it is thick. You cant cut it. Now these Screen protectors exist for pinball on the web from $15-$59. They are heavy, and do cost. So, a sheet the size at a translite, would run about $160 my cost FOB, or, since its not likely Id need a pallet by sea, about $185 by air.
There is no market for it because Invisiglass, I understand solves this, and benefits the whole game.
To help with a tube issue, people have put Gel Sleeves, Heat resistant paint on 1/4 to 1/2 the bulb,
a light shield or plastic to diffuse in front of the bulb. Many different tricks, but only you know what brightness is right for yourself.
If you have an LED kit with issues of brightness to the translite, you can diffuse individual strips, with
"lens" that you make, or if its everything, a thin sheet of diffused "paper" or "plastic", behind your translite.