There is a ton of anecdotal evidence on the interwebs about the photosensitivity of fungi, ie, it governs the direction of pin growth, fruit colors, etc. suggesting a circadian rhythm of sorts.
There are older papers out there that do document light sensitivity in the red/blue ranges. However, none that I found have actually documented chemical changes in the fruit itself, just the changes in the structure of the fruit. (If I remember correctly, it was around 100 species that have been documented as photosensitive to some degree.)
I personally have debunked monotub side pinning being caused by light. Compaction of the substrate and limiting moisture exposure to the sides of a mycelium cake has all but eliminated side pinning for me. I digress.
So, I am just looking for new studies and research papers on this subject. Eventually, I will probably conduct my own experiments, but that is for another day.
Cheers!
To your point of chemical changes vitamin D2 is produced by light exposure. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6213178/ It specifically refers to UV light, but the chemical changes are due to the light itself, not a metabolic process.