>>535593437
They should just refund the whales and make merging merge everything, and let either standard or alt units raise the merged unit's discipline (maybe with the standard variants granting less discipline experience). For instance Yeka's merged discipline would read:
>Continuously increases each stat, Skill-bind/Spell-Bind Tolerance increased further, with HP and MP increased even further.

>>535587527
Go to the training room and there will be a merge option. It's worth checking both ways around (merging into the original or into the new unit), unless you know boons/BPs. If you haven't levelled their class change, then you could compare stats there instead. Here's my Yeka for instance; pretty sure left is showing the gains from the higher BP of new Yeka, while middle is showing the gains from grade exams, and right shows the resulting unit (merging the old into the new).