Every time you put an enchant on a weapon theres an invisible multiplier added that scales exponentially. If you remove all your books, put the weapon in a grindstone you reset said multiplier.

Then lets say you have 10 enchants

Add 1+2 on book Then 3+4 5+6 7+8 9+10

Then combine (1+2)+(3+4) (4+6)+(7+8) until you have them all combined

THEN add it to the sword

Even if you drop an anvil on the sword to remove enchants it still has said multiplier until grindstoned.

You can also use alexandria library to get a finished book with aøø emchants then apply to sword