If anything, just make a 'Freecure II' trait that makes it proc off lilies. Sure, it's relatively rare to need to cast Cure II after a lily heal, but at least it happens, specially while leveling.

It's not that Freecure itself is a bad trait - it's useful between lv 30-50, but it's pointless after that because Cure I itself becomes pointless. Even if, for whatever reason, they removed Tetra and Solace, people would still just cast Cure II, rather than spam Cure I. That's how pointless it is.