I don't think that vibration will cause the spring to wear into the cable sleeve. This particular spring was of the "Goldilocks" variety - not too stiff, not too flexible, just right.
I'll keep a close eye on it though and report back if it causes more probles than it cures.
That being said, I like SST's split fuel line idea too! If this spring doesn't work as intended that's what I'll do next. Thanks for sharing it SST.