You’ve specifically asked about metal bands, and TBH I can’t really think of any who are completely style over substance. Cradle Of Filth (whose music I love, BTW), have in the K-State Octagon of Doom shirt and by the same token and past offered ringtones to their fans, but seem to mostly stick to the aforementioned trad. fayre these days. However, the bands musical output has always been interesting and entertaining IMO, so I tend to give them a pass. Then there’s Behemoth (another band whose music I like), who do the usual range of shirts/hoodies/patches etc., but also coffee, beer, a Zippo lighter, candles, figurines, and a video game. Now this might just be me being an old git, but I don’t like to feel that I am being targeted as a customer of a band. I like vinyl (for a few select artists), and occasionally cassettes, so if they are offering a number of vinyl formats for a release, then they should be relevant and not just a slew of coloured discs, or different sleeve designs that don’t in any way relate to the music.