What phono cartridge is suited for metal and heavy rock?

It probably depends on your own preferences more than the specific genre. I do very much like MC cartridges because they’re so detailed and lively. But I tend to prefer the warmer voiced MC cartridges like Koetsu, Benz, Shelter. I really enjoy these cartridges with some heavy metal, but some might prefer that music with a more tipped-up sound.

The 2M Blue is indeed slightly bright, especially compared to the 2M Red (which is vastly inferior to the Blue, overall) but it certainly doesn’t have the detail or drive of a good MC. The Ortofon Cadenza Red is kind of a good analogue for the 2M Blue in MCs - slightly lean, slightly tipped up, but great drive and detail that can be a lot of fun with rock & metal. Then the Cadenza Bronze model takes that and adds warmth, and fullness (at a higher cost) - even better IMO. That said, a good deal on an imported Benz (audiogon ads) is gonna be hard to beat for the money and I do really enjoy some heavy metal on them.

I’ve enjoyed stylus profiles from plain elliptical to extreme micro lines / micro ridges / etc so I wouldn’t get too hung up on that. What IS important is to get a nude stylus (which your 2M Blue already sports). And cantilever material will probably have a bigger impact on sound than the stylus profile.

Phono stage (or SUTs) is gonna become an even bigger deal with MCs.

iv always found most metal music badly recorded.

It can be really hit or miss, even within a band’s catalog. It can also get expensive because even the ones that don’t sound great can go for a LOT of money, and you can’t trust the reviews on DiscOgs AT ALL. But there are a lot of really great sounding metal records out there, and even some spectacular ones.

From my own modest collection, the following are spectacular: Avantasia’s Metal Opera 1 & 2 and Wicked Symphony (Moonglow comes close), Iced Earth’s The Glorious Burden, Rage Soundchaser, Metallica "Black" 45 RPM box from 2008, Metallica Load OG, Helloween Keeper 1 & 2, most of Magnum’s catalog, Iron Maiden Brave New World, Blind Guardian Nightfall, Nightwish Decades box, the Edguy box, the Megadeth classics (RIP, Countdown), Van Canto Voices of Fire, Opeth Morningrise, a couple from Porcupine Trees, the first 3 OG’s from Cirith Ungol, Danzig...oh and Warrant Cherry Pie sounds ridiculously good but that’s more hard rock / hair metal. There’s loads out there worth chasing, and worth playing on a great hi-fi.