Unsure about IA, but gloves are typically advised against[0] unless you have a suspicion that the book will be dangerous (arsenic ink in bindings[1], dust, mold or frass (sadly)[2]). Hand-washing before is typical advice but YMMV
I get the points against gloves in your links, but from my experience my hands will constantly leave fingerprints and oil on the books no matter how much I wash it.
How do they avoid this issue? Or just don't bother?
The advice I was given when handling some of the books at the university of toronto's rare book collection was to simply not directly touch the parts that matter if it can be avoided. Turn pages via their margins.
