I remember the stuff about him going to a vocal coach, but I always assumed that was for cleans rather than growls/screams, especially as Battles is majority cleans. If he did get some coaching for harsh vocals too then good on him, he's needed it for a while imo. You're right that he's never had to cancel any tours or take time off, which is somewhat impressive. Stanne had to take a year off because his screaming technique had fucked his voice up. You can notice a very distinct change in his voice between Damage Done and Character. The technique he used post-Damage Done is far safer, although I admit to preferring his vocals pre-Character. Still, safety first. He probably wouldn't be doing vocals at all now if he'd continued on the way he was. Anders should probably have considered taking time off or adapting his technique around the same time though. I mean, case in point is Seoul 2002: You can't listen to that and think that it sounds healthy. He's even reaching to his throat/chest area a few times. It's a bit hard to watch. Lots of bootlegs from around that time period (2001-2003 especially) are similar - his vocals sound worryingly strained. He got it together for STYE and Come Clarity, but in the long run I'm not sure that helped as on ASOP he sounds terrible, and that's with studio magic on top.