I just build whatever i want to build and NEC can go bother someone else.
Use common sense. If you think something might potentially someday fail catastrophically. Make it so it doesnt.
Anything may fail catastrophically, the question is how likely is that to happen and who would get the blame for collateral damages.
If nothing happens, nobody cares. And obviously it is the ideal outcome.
But if something does happen, mainly when contribution of something else gets involved (someone splashes or throws something on it by accident and it catches big fire), you may get in trouble for proving you have fulfilled your duty to made the design sound.
Using certified components according to their manufacturers instruction (so observing the material limitations for the fixture body,...; to ensure the certificates remain valid) is a way to fulfill that duty.
Getting recognized agency certification for your design is another way (obviously usable only if you want to produce them in quantity as a commercial manufacturer).
But otherwise you could fall quite short handed defending yourself in the eventual liability case, regardless what would be the technical merit. You would be arguing against lawyers, not engineers...