Hello, first and foremost really nice and clear guide, good job! Good to finally know the point requirements for leveling up.

I've got a suggestion about recommendations (in case you dont consider getting any ninja frags) - even though refines (when you use them, they are always a good option), it may be better in a long run to invest in clothing in terms of power. When you look at the current other clothing prices (eg. kimono, 50/frag) and compare that to refines (less than 25cp - shop price) and notice, that summer clothing costs only 25% more than refine, that puts refines in this event in a really bad light (this applies to free point spending).

Let's say you ac*ulate 100 free coins during that event, neither 5 refines, nor 4 cloth frags won't give you immediate noticeable power HOWEVER in terms of item value, getting refines gives you 5*25=125cp and getting summer clothing gives you 4*50=200cp. That being said, if you want to know what might be better in a long term, I'd personally go for cloth. I assumed 50cp/frag, because sooner or later price will drop and will be equal to other clothing.

@Kaislee you forgot, that if you use ingots, you also get the benefit of daily spend, at least 4 times so thats another +- 6k value of items