Kydex isn't awful to work with but there is definitely a learning curve. You mentioned using it to route air to anintercooler- I don't think kydex is going to be a good choice for that application. Since it's a thermoplastic it gets malleable above a certain temperature and loses the shape you created it in. While you're driving down the road it with fresh air flowing over it there's little issue but when you're stopped and the intercooler heat soaks, engine air is heating all around and hot pavement is radiating, the kydex will lose whatever shape you've created. I've had customers leave kydex holsters in the car on summer days and the holsters have been cooked, temps around an engine bay will be much higher.
I would use carbon fiber, fiberglass or aluminum before kydex for this application.