Here’s my take:

One more thing - ran out of main color and needed 1/4 skein to finish left collar.

This is quite challenging. There is a lot to intuit out of the instructions, particularly in regards to the front bands. You also should feel really comfortable with keeping track of your colorwork pattern in the midst of multiple points of shaping.

All-in-all, not impossible, but be ready for some serious work. The pattern is generally written pretty well, however I do believe it could have been another two pages long with more clear instructions on explicitly how the stitches along the front bands are picked up, and how often to pick them up. If you are very experienced you can figure out what works best with trial and error.

There is also no direction to preferred method of finishing the raw steek selvedge. I split the plies of my CC and used a single ply to whip st down and back with the cut edges slightly folded under as best as possible.

Additional errata notes: the “one-row buttonhole” instruction in the Notes repeats the row instructions within the pattern, so watch for that.

The buttonhole instruction should either end with 3 sts (not 4) at the end of the buttonhole or should read, “pass last cast-on st over sl st and return st to LH ndl”.

For the left band the repeat should be “repeat the last 2 rows seven more times, then work Row 1 (WS) again, then work Buttonhole Row (RS)”. Then, “repeat prev 16 (not 15) rows 6 times more”.