I think especially the f2ps should do the freezing. Collecting coupons looking out for the perfect cycles to use your hard earned coupons, to be able to compete by keeping your level low but power high is basically a f2ps life. After 80 there is not much which can contribute to your gameplay, you can start as early as you want or you can consider a level which leveling up won't benefit as much past that point. Long story short, yes f2ps should freeze. Now with infinite illusion farming coupons has become easier than ever.