I have 5 meters of FEP tubing kicking around from a half-assembled Enraged Rabbit Carrot Feeder, that I got as a cheap substitute for teflon tubing, and I figured I could use part of it as a reverse bowden tube for the surprisingly long and elaborate filament path on the voron 2.4 (which has to go through a bulkhead and then around a 270-degree corner.)
unfortunately, while FEP is cheap and feels a lot like teflon tubing, it's significantly higher friction! and that means its practical bend radius for pulling filament through is nowhere close to what you can get out of PTFE -- I was having really awful underextrusion and jamming problems, particularly with PLA, until I swapped it out.