I just received the key mod for my HS2. I looked at the 3D print quality of the parts and believe that a pretty good replacement insert could be made from an opaque filament. The clear/white part looks a bit like cloudy ice, not quite transparent, but far from solid. If all of the inserts were changed at the same time, with good LEDs under them, I think it could be an economical and viable stop gap solution until something else becomes available. I'll snap a picture when I get a chance.