Wonderful design! It definitely makes sense for an environment of travel. And now I understand the origins of the "big books prominently hanging from clothes" that's seen in some fantasy settings. For example, the Witcher series [0] or Warhammer [1] will sometimes have characters prominently wearing a book of spells or lore of some sort. However, these series don't seem to have thought through the actual design/binding of such books in a way that would make for easy access.

As a possible future fashion, I would love to see something like girdle book binding used for devices like smartphones. I still have momentary annoyance when pulling a phone out of my pocket, so reducing that friction would be interesting. I see there is already such a case made for reenactors / hipsters [2].

[0] https://2.bp.blogspot.com/-JZ5lMsQEYgE/VvzXtponQ4I/AAAAAAAAB...

[1] https://vignette.wikia.nocookie.net/warhammer40k/images/0/04...

[2] https://www.etsy.com/listing/155624836/custom-leather-smartp...