So recently I've started using 890 Fury of the Burning Sky. It had 1137 mastery and has a decent ~500k proc (scaling with mastery) so I thought it is worth giving a shot.
According to the description on trinket, it works only for ranged attacks and spells. After some testing it seems that it can proc off (below is a list of "spells" that enh shaman has):
Fury of Air
It doesnt seem to proc off:
Hailstorm [But it works on flametongue hit, huh? Weird.]
In Simcraft it falls behind in single, but it is a decent AoE option.
That's some good sleuthing but I'm afraid, won't be a surprise to that many people.
Enhancement has been able to use spellcaster trinkets this whole expansion, most of our toolkit counts as spells.
Unfortunately none of the spellcaster trinkets in Nighthold are really very good, so they're not particularly worth rolling on.
One thing I'd note is that you're actually mistaken about Crash Lightning. If you untalent Crashing Storm it will never proc a spellcaster trinket, it's only the hits from CS that count as spells, CL itself is a weapon attack.