I have a chest of enchanted books and it successfully sorts them by enchantement (the "Knockback II" are at the same place for example), but if I have a "Knockback I" and a "Knockback II" they are not put together and are very far from each other, it would be cool to put them together

By default items are sorted the same way as the creative inventory.
But sorting is fully customizable... the original author attempted to explain how https://github.com/jsnimda/Inventory-Profiles/wiki/Add-a-Custom-Rule