User blog comment:Mich, Michele & Kuhla/Future Units Preview/@comment-26336535-20160225002555

Found a list of the customizations if anyone's curious. Here.

I'm not sure what's correct, but so far I've found the only requirement for customization was having UBB, so you don't need to max the unit. I might have missed something. So once you have that, you have 10 SP (the currency for customization). A sphere frog gives an additional 10, Burst Emperors give 5, Burst Frogs give 1, and all other units have a chance of giving 1 (unsure about imps and such). The max SP you can have is 100. You can then spend it on customizations, which vary in value. I believe if you want to reset the SP points you need to spend 3 gems.

If I'm wrong about anything, please correct me. I didn't read too carefully on any of the pages I found.