I've joked that all S ranks should spawn with an "Enraged" buff that makes all their attacks lethal, and makes them immune to damage that lasts like 5 or more minutes. That way, there is a clear timer before they can be engaged with, and it punishes players on the spot if they pull an enraged hunt mark. They are supposed to be "powerful marks" after all. One of the big reasons why players are significantly more respectful of 'pull times' at big FATES like Archaeotania or Chi because it is really not practical to engage them alone. Another reason why toxicity is lower at FATES because the rewards are less lucrative than hunts so what could also help is to reduce the amount of tomes hunt marks drop, but that would likely be super unpopular.