I suppose it is a matter of what is a reasonable amount of time to wait once something has spawned. Sometimes somebody will shout and then seconds later it is dead by the time you've ported or travelled there.

It is kinda something that has put me off doing them, whilst I have contributed to hunt groups before, but sometimes a hunt just spawns and you're in a position to join but often or not its too late.

I am for immunity or some other method, because it doesn't have to be a long timer to give people a chance to run over, and yes there will always be latecomers, but this would give a better chance, particularly on any hunts that are quicker to kill.