Book bags are amazing. Over time, however, whether you're a collector or an avid author just carrying around your own stuff for impromptu copying during RP, you can end up with a very heavy bag that can suddenly lurch from 2 lbs to 12 lbs because the book bag has no weight modifier. If you're a noodly-armed wizard, arguably very likely to be toting books a lot, this is a significant problem.
I think it would be a huge QOL feature for book worms to have craftable (or maybe just lootable, why not?) variations of magic book bags that reduce the weight of what's inside.
Given that books are hardly mechanically impactful such as resources, I don't see how this could be such a bad feature.
