Whatever you call a system, doesn't matter.
There are also cross-over systems.
As long as roots get nutes, water and oxygen, it's ok.
You can run HPA or LPA in a system that is designed for F&D.
But when the rootball is becoming bigger and bigger, it can give problems with getting enough water and nutes to every single roothair.
The advantage of HPA is that the droplets are extremely small and the roothairs take up the water with nutes more easily.
This only works if your pump runs for 1, 2 or just a few seconds.
Because if you run the pump for 30 seconds, the droplets become bigger drops, and that you have the same result as LPA.