Amsteel or such for offshore cruising lifelines

[Brian Duff]

We use 3" lengths of slpit tube white vinyl shroud cover (like a lot of people use to cover thier stainless steel rigging to make it easier for sails and sheets to pass over, and for mold and corrosion to live under....)

and we 'clip' this stuff over the spectra where it passes through stanchions. looks ok and is quick and effective.

[osteoderm]

There's an old Formula 40 cat daysailing down here in the VI with singlebraid lifelines. I'm pretty sure they're using Yale Maxibraid, and it looks very slick. The spectra is served with contrasting braided whipping where it passes through the stanchions, and is furthermore seized at each stanchion.
Reading up on a few different offshore class rules, I see that wire lifelines are usually the only acceptable material. I'm fairly certain that this has been discussed on this forum before...
Just wondering aloud here: could somebody's insurance be compromised if a surveyor flagged non-metallic lifelines?
I'd love to have 1/4"+ spectra lifelines, lighter than stainless, and of a more comfortable diamater, but it may be hard to find any standard stanchion with holes large enough to pass the line. In any event, I see chafe as the most worrisome drawback.