Feature to counteract strange bug
I am receiving a bug where the text does not display in the held item. I have deduced it is not a resource pack or shader issue. As I am playing with over 200 other mods, narrowing the source would be too tedious. The ability to hold CTRL on an un identified spellbook, and see it's word components in the tooltip would solve the issue of not being able to discover new spell words via book. Or the ability to sneak+right click to open the pages like a written book or guide book UI.
I have found the source!! The text inside books does not scale with item size when changing it using pehkui. Everything else I tested worked just fine, but scaling the item held (pehkui:held_item) value with that mod, does not scale the text with the model.
Noted, thank you for the report! Currently if it can't be read, the solution is to convert it back to an ordinary book for reading, but I can definitely look at adding additional solutions, and potentially adding compatibility for mods which might move / scale the item model.
I will leave this issue open until either / both solution is implemented.