I honestly didnt know you could d4 into fans after clipping them with a fan! I just looked in the lab; you can also use d4 into square wave for a fullscreen knockback.
Just keep in mind that d4 into specials aren't natural combos and SW is super punishable if they block. If I see another Kit player use SW more than once I generally start to think it's a fight I'm going to win. (mostly if it's used in the yolo sense, than say distance closing)
I never really looked at fan advantage until after switching to Fearless. Since you can't lift after 12, or b231 I had to start hit confirming into fan as an ender and trying to figure out what comes next. One of the more useful ones doesn't make sense for FF since she can go for damage off of everything, but ending in fans leaves them at a range tempts people to feel safe at, but are actually still in b2 range. At -9 or -10 (b231, fan) means their options are very limited and generally about all people can do is down poke if they have a 6f. Some which 6f d1 character players do tend to do there.
Most characters can't even jump up or in if you chuck another fan, so I try to tell myself to just do that and see how they handle the situation. If the jump, doing b231 is mega dangerous and it's better to just make them take the second fan. Just b2 alone is a decent test as well. If you get them respecting getting hit by fan, you can start moving on to stuff like b231, b14, jump in, or dash in throw. F2 isn't a bad option either. It has one less frame startup to fight off pokes, and its string is quite a bit better at dealing with jumping. It's prone to getting low profiled though.
At really close ranges fan is like -9 and may leave you in b14 range, or at least close enough to blow up any button they press. It's not the best situation to be in though given you basically would have chucked a fan right in their face and risked full punishment, but you know I've done it.
