can i modify spells in spell book? And how can i set the number in an ability icon?

i thought i saw a trigger or something that said something about spell book but i can't find it
anyway my question is, are there trigger actions to modify which spells are in the spell book?

also

you know how learn skill ability has a number in the bottom right corner representing how many skill points you have. well can you add that feature to any spell and how would i control what number appears?

thank you for answers

Actually if the spell book has the bloodlust ability, and the unit A has that spell book ability, you can remove the bloodlust ability from the unit and the spell book loses the bloodlust, if you want to add it back, you'll have to remove the spell book and add it again.

But for some reason removing abilities resets their cooldown.

Weaaddar's Drag and drop packback comes with a spell book system where you can addand remove spells from a spell book

So let me get this straight your saying that inorder for me to adjust the abilities in the spell book i have to give it all of the abilities possible, give the book to a unit, gie the unit the abilities, remove the abilities from the unit then transfer that spell book to which ever unit i want? wouldn't this be a bit inefficiant?

No, all you have to do is give a unit an all-including spellbook and then remove all the abilities except the ones you want the unit to have from the unit, and they will be removed from the spellbook.

Is it possible to use the new 1.17 actions to level unit abilities inside spellbooks?

what is the maximum amount of abilties that a spellbook can hold?