I'm not sure if it's a bug or a side-effect of a system change, but enemy Gaping Wounds does indeed cancel your salve on every damage tick now (not just crits), making Carathos extremely difficult.
Valgar's Flame Nova covers roughly 3/5 of the arena but can still be avoided by hiding behind a pillar. It's just that the damage applies a second after the visual effect so you run back in too early and get hit. This could use a change I guess, kinda counter-intuitive.