I... fail to see why that's necessary.
Weapon enhance was probably never the intended way to level your himes in the long run, considering they get XP for each clear in some quest, it's a simple process of gradual levelling.
Enhancing weapons and eidolons on the other hand... you'll actually see in the long run that they're quite easy to max level with enhance, especially with the inclusion of SR enhance mats in gemcha.
And union events... don't get me started on how many mats you can farm there.