I have wondered about it myself, but it hasn’t caused any problems in the 6 months I’ve been printing. The curing station cover is supposed to block 99.95% of UV rays according to Elegoo’s website.
And having to go through the curing station cover and the printer's cover means that even less gets through. Basically 0.05% of 0.05%, so effectively zero.
Also curious about this, don't know the answer. I've been keeping mine right next to each other simply due to a lack of room. No ill effects yet though, and I've cured and printed things at the same time before