How much longer will 6 Spatchcock chickens take vs 2?

My first cook on the MAK 2 Star a couple of weeks ago was 2 Spatchcock Chickens. Preheated the MAK to 400º and then set it to SMOKE for 45 minutes of Apple smoke. Bumped the temp to 350º till the breast hit an IT of 168º. Pulled the yardbirds and rested them for 20 minutes. Took just shy of 2 hours total (not counting the preheating and rest).



Have been asked to do 6 chickens for my wife's birthday party Friday and I'm trying to figure out how much longer it might take to do 6 vs the 2. Figure on using a double rack and doing 3 on top and 3 on the bottom.

Will the MAK take a little longer due to the amount of chicken or will it just take it in stride?

I don't have a MAK, but if the chickens are about the same size, as the 2 you did previously, I wouldn't expect the cooking time to be much different.