It is complete!
I followed the UNdirections closely.
Included Phoney Seams up each side and underarm...
Knitted in a secret message...
And it fits! (And matches both our house and Mr. D's spidey boots.)
This was an indescribably enjoyable experience, the first of many to come for sure. He's worn it voluntarily twice already, and I only finished it on Sunday. My neighbor, also a knitter, but one who's not heard of EZ, has already asked me for the pattern. My spouse already asked, "How expensive is the yarn you used?" and has been ogling the saddle-shoulder or hybrid.
I wasn't sure how I'd feel about the hemmed bottom edge -- which I didn't photograph in progress because I just couldn't stop knitting -- but I love it. I knit up in the purl bumps, decreased by 10%, wrote my secret message, and sewed the stitches on. (This got easier when I thought to use open stitch markers to mark ahead a few stitches so I could keep it straight.)
In total I used 2 skeins of the blue and one of the red. Had to break into some green I had stashed for the message letters in order to keep enough blue for the final hem row and sewing-up yarn. The stripes made a few burbles in the fabric when I wove in the ends, but a good steaming evened everything up and I'm just so happy with it.