Teflon lines "take a set" and so do "rubber" lines.  That doesn't mean they become hard or that they will have problems if they are moved around some. 

 

I have used fire shielded SS braid Teflon lines forward if the firewall since the beginning (first flight 1996, 900 hours). The oil cooler, remote oil filter and all fuel lines, including the one connecting the gascolator to the boost pump, are such lines.  I have moved the location of my fuel flow sensor several times and the fuel lines have easily followed.  NP.

 

I run SS braid Teflon lines from the wings to the wing mounted Facet pumps and from there to the header tank.  The same type of lines are run to from the header sump to the drain and firewall, thus making the canopy/header deck easier to remove since I can lift it enough to get my hands and wrenches in from the side an on those connections.  NP

 

I chose SS braid Teflon for the interior because it cannot work harden and crack, and it has no life limit.  I chose it because it because of survivability in case of a crash.  I also chose it because I am a lousy Al tube plumber.  I might even use the Teflon lines if I were to build a still.  I assembled all the fluid lines for my plane and the most reliable are the SS braid Teflon.  The only drawback is that all the connectors are steel and, along with the braid, such lines are a bit heavier that hard Al lines. NP