Never heard about or seen plastic lines, but I would imagine that NHRA and other sanctioning bodies would not approve of them.
The question is: will RACE fuels over time brittle the plastic or even start to chemically break it down/dilute it?
If anything good comes out of it, it would be for cooler fuel over the distance of the chassis.
Talking along those lines, I once thought of creating a slim silo type of ice box that runs the straight length of the fuel line with the fuel line impregnated in it that could be packed with dry ice to super cool the fuel as it sits and travels through the line on its way to the carbs.