My primary goal was to add incompatible enchantments which ended up being totally out of my league, extremely difficult. After wasting up many hours, I ended up with just adding the enchantment combination max level. That allows the user to have an enchantment max level and an enchantment combination-maxlevel (e.g.: max level for unbreaking = 5 but you can combine the unbreaking up to level 4. For level 5 you are going to need a book). I made some cleaning changes so there might be some unexpected bugs. In order to use the new feature you are going to need to reload your config files!