[godelski]

Glass blocks UV-B and UV-C, but not UV-A (unless you have a film). Many mushrooms can be enriched with UV-A, but UV-B is best. So yes, I agree, better to place outside in direct sun (or window open). But building the habit is the harder part for people tbh.

[contingencies]

Also transparent polymers will generally break down with prolonged UV exposure.

Alternatively to leaving them exposed outdoors, you can use quartz.