I took a moose at almost 300 yards. Absolutely no time to dial. Luckily Moose is rather big, and the shot took out the very bottom of both lungs. Yes a little low, but I got lucky.
But my point is, no time to dial. I aimed a little high, not high enough. IMO, holdover lines are necessary.
300 yards, and the animal knows you're there. The animal is whiffing, and looking your direction, and slowing walking off. You just go with your gut instinct that you built with range time. Dialing is out of the question.