This color glows, after using this yarn on my Owen I wanted a loftier softer feel so went with 7’s overall. 6 on ribbing. I’m pretty sure I needle sized down on the collar as well (I swatched the garter and mathed).

Mods:
-i-cord bind off on collar/pockets, I imagine they’d get tugged a lot so I basically made 1 at every edge and handed it to a live needle and finished the entire cord at once
-I adjusted the cable placement mostly so it would lay flat (the measurements my mom gave me were for a T-Rex, a massive chest and 7” arms)