As far as I can tell, the derating requirements of 334.80 only apply to more than two NM cables with two or more current carrying conductors if you don't maintain spacing.
IMO, since the spacing is not defined, it could be 0 to 1mm or even 10-feet... there is no specific distance required top to bottom, or side to side, whether thermal insulation is involved or not. Likewise when any number of NM cables is installed through the same hole in wood framing whether it is to be draft stopped or not.
So, I guess if you have metal framing... no worries?
The way I see it, you could drill a single 1-1/4-inch hole in a wood top plate and run as many NM cables through it as will fit without derating, as long as the cables are evenly stacked top to bottom and side to side. There also doesn’t appear to be anything preventing you from changing direction of the cables to a different position once they pass thought the hole in the framing, as long as they all transition in the same direction with the same spacing, which in this case, could be any desired amount.
I don't write it... I just read it.
