You can actually get 5 aerial charge shots off before you're forced to land. Neutral square can be as many times as you want in the cancel chain, but not directly after another neutral square.
So like double jump > charge shot > back square > charge shot > up square > charge shot > forward square > charge shot > back evade > charge shot
Or whatever combination you want based on positioning.
So like double jump > charge shot > back square > charge shot > up square > charge shot > forward square > charge shot > back evade > charge shot
Or whatever combination you want based on positioning.