Hey man, I know this isn't really what you asked for but I'm also a metal enthusiast and as it happens have these songs in my playlist. Good songs
Plague Years - Evil One
Moondrop B2 Dusk:
- Too warm for this song so instruments blend together in general
- Cymbals mush together
- Handles the bass and vocals fine
Thieaudio Monarch (with EQ):
- Handles everything fine
Catastrophist - Trivium
Moondrop B2 Dusk:
- Cymbals mush together or just get lost (see 1:39)
- Not fast enough to handle the quick kicks in the bass. Turns to mush. (see 3:08)
- Handles the guitars and vocals fine
Thieaudio Monarch (with EQ):
- Handles everything fine
Ten Thousand Crows - The Lovers
Moondrop B2 Dusk:
- Again, cymbals mush together or just get lost
- Again, not fast enough to handle the quick kicks in the bass
- Handles the guitars and vocals fine
Thieaudio Monarch (with EQ):
- Handles everything fine
So I'm sure you can see a pattern here which is why I can't recommend a tribrid enough for metal music unless you don't listen for the cymbal hits...
When I receive the Geek Wold I'll be listening to see how it does with the busy cymbals but, similarly, won't expect it to be able to keep up with the kicks.
You've already got some great picks but here's some other metal recommendations on evaluating IEMs:
Orpheus Omega - In Time for the busy cymbals and drums (just insane drum work in general:
Orbit Culture - The Shadowing for the busy instruments
Even the Monarch can't deal with those two songs which makes me sad but realize how much potential is left for IEMs in the future.