Mid August is a fine time for planting wheat, with mine the deer ate it right down to the ground by snow fall but it came back fine.
But if your talking 2F your reproduction rate will be much lower and of course regeneration is not a factor in talking PPA. So with a chance of germination out pacing recruitment it really is beyond a biological science to state a planting rate that will guarantee a successful harvest that does not meet MSY over the long term.