Almost anything black nylon has inherent UV resistance greater then white Nylon. can;t imagine under hood UV on a bolt head of nylon would ever succumb to UV issues. They are cheap enough to toss rather then reuse.

Awhile back it was mentioned the manifold issues are similar to "hydraulics", if you discount the the concept that a liquid is for all intents and purposes non compressible and air is, and the speed of the pressure spike is much faster in a liquid (for example speed of sound in air 343 m/s vs 1461 m/s in oil), allowing less time for flow to displace volume/pressure thru the burst panel.

Nobody has an issue with a partially separated TR top acting like a WO stuck throttle?

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.