No Sparge Qns

Hi there, Im planning a RIS no sparge brew in 2 weeks time after a porter than I'm brewing this weekend, so I can pitch the beer onto of the yeast cake.

My qns is, do i have to add more dark grains as well for the no sparge as I wld for all the other base and specialty malts? Wouldnt want to end up with a beer that has too much burnt flavour, or too little for that matter.

I was told that I should also scale up the roast malts as it should be across the board for all malts.

TIA

scale up the whole recipe to make up for the loss of efficiency. if you selectively scale up only some grains you will not have the same beer.