Yes, it may not be good. However, that study used thin material samples - and those are particularly vulnerable to UV. Thicker materials are more resistant because the UV doesn't penetrate into them.

If you want to deploy UV in a specific space (think conference room or hospital ward), I don't think the problem is that hard. There are coatings you can put on top of existing plastics which protect them from UV light. However, I imagine that customer education around managing risk to plastics is going to be a key issue for UV companies if they are to succeed.

This is fair - but i think you are undershooting what is normally thought of as plastics - because it includes most coatings. So the stuff sprayed on your cabinets, rolled onto your floor, paint on walls, etc, are all polymers of various sorts that are not uv stable.

The average dry film thickness of these things is going to be a few mils total (~100% will be 2-6 mils). So very thin.

Pretty much any indoor coating is not going to resist UV well, whether it yellows or not. The acrylic based resins i guess will be okay. The reason all the lights in houses are UV filtered is not entirely about safety - the amount of UV radiation they would produce is fairly miniscule from a human perspective - but if they weren't filtered, leaving the lights on in your kitchen too often would likely, over the course of five years, be really bad for the cabinets, floors, walls, etc.

I think this in practice, the killer. Even if you could deal with plastics themselves, there is just so much you will now have to protect or change.