Thanks guys-
Ryan and Ralph- I've seen both of your solutions on build logs, but I also asked builder support and was told that it would be fine to just poke another separate hole in the fuel line passthrough grommet and stick it through there with appropriate chafe protection/standoffs to the fuel line.
I'll admit that it's probably just a personal hangup but it makes me queasy to think about securing a wire to a fuel line, even if it's just measuring resistance, so I'm weighing both of your solutions.
Either one of you have problems with your solution? would you do it the same way again?
my wire bundle is pre-fab and already set up to run that wire from the center tunnel along the center section spar box (front side, in between, or aft side, I've got enough wire to do either), so I can easily use any of the 3 suggested solutions. I'm just weighing the pro's & con's of each