We should never make blanket statements about what techniques work and don't. Practicality in and of itself is not objective. A person learns how to defend themself from realistic martial arts and self defense training where they learn how to apply technique in a noncompliant environment. But simplicity is always a good guideline. There's no need for flashy techniques in self defense, and they're only going to work so well against an unskilled person. An unskilled high school student is also a lot different than a drunk, angry gang member, or someone with experience street fighting too. You can't compare what you've seen to the reality outside of school. It's a lot different when someone is seriously trying to harm or kill you.
If the opportunity presents itself, there shouldn't be any rules on what is necessary. But why make the situation longer by doing jump spin kicks? One could just end it with a simple set of strikes, takedown, or submission. It's not a contest when you're trying to defend yourself. You should be looking for the easy way to end a situation.