Its very easy to cheat at Quality by decompiling product into letters if you don't get desired quality.
Solution is that a configurable (20% to 30% by default) setting by which 20% of the letters should go missing on decompilation.
Decompilation shouldn't be 100% free of cost, it should involve some losses, like recycling.

Or maybe decompilation should only loose letters if quality mods are involved. if decompiler has 10% quality, then maybe lose 2x to 4x of the letters, like 20% to 40% letters.
But if no quality mods are involved, then no losses.

I personally feel like a lossy decompilation kind of defeats the purpose of the mod, so I just disallowed quality outright. It's not a great solution, but it's unfortunately the best that I could come up for right now given the constraints of the modding api. Thanks for bringing this to my attention, though ^w^