I attempted this and accidentally drilled through the printed piece. Take it slow if you go this route.
Are these measurements from the very front of the Y-rod holders and idler/motor mounts, or are they between the square (not angled) parts of the mounts?
Apologies if this isn’t how it’s supposed to be done — I edited this step to use a M3 Nylock hex nut for the yellow instruction. Just a personal preference as it will help secure the part cooling fan duct. I use a Nylock hex nut here on my MK2S.