Minecraft version: 1.12.2
Scrolls have several advantages: they don't require a tier of wand to cast, are rather cheap, and (as far as I can tell) have no cooldown. They also have several downsides, namely their one-use nature and inability to stack. From what I can tell, casting one will also delete others of the same spell in your inventory, but that's probably a bug.
But what if scrolls were a feasible way to cast? Something like a spell book that you can put scrolls into. Whereas wands can infinitely cast certain spells for a mana price, spell books would cast a greater variety of spells for a mana price (or not, since scrolls already require crystals), but are limited in use. For instance, the apprentice tier could have, say, 10 slots, accessed by shift-right clicking or something, each accepting a single scroll. This means it can cast 10 different scrolls once each or one spell 10 times or anything in between. I feel like this would add an extra degree of strategy, allow scrolls to become more useful, and create a new class of casters altogether, who would "prepare" spells before combat like a D&D wizard.

As of Wizardry 4.2, scrolls are now stackable. I may add a scroll-holding item in future.