I worlk for Parker Hannifin on hydraulic hose, tubing, pneumatics. Parker has a product, HTFL tubing, which is a high temp nylon tubing product, used on a lot of over the road Class 8 trucks:

https://ph.parker.com/us/en/diesel-fuel-tubing-htfl-pft-series

HTFL tubing works with standard compression style tube fittings, so the tube can be attached to a pipe thread pipe, SAE straight thread port, Metric and BSPP striaght thread ports. It is somewhat flexible to route through relaxed arcs. Can even be thermal formed on a simple jig wiht a heat gun to thermal set it to a specific shape. Might be an option for you?

The product should be available at any retail counter at a Parker distributor, and most any Parker Store.