What a special garment!
The directions are well written.

Tip:
When dividing for front and back, instead of knitting up the Back stitches that will go onto a holder, simply knit those stitches directly onto another US 8 circular needle. Put stitch stopper caps on this needle to keep the stitches secure.
One can work the front / back, neck / shoulder shaping similarly.

Quandary # 1:
I don’t know the intent of the designer regarding the transition from the main section to the collar:
continuity of the pattern or not.

For continuous transition:
when working the first collar row, pick up and work the pattern row vs pick up and knit as written.
When ending the front and back, the stitches placed on holders were knit, RS facing. When working the collar, one is working from the RS again, in the round.

For a break in the pattern between the body and collar:
pick up and knit.
This results in two st st rows before commencing with patt.

Quandary # 2:
Collar directions say to work until patt meas 9”.
The collar begins with a join with held stitches from back neck, picked up stitches along neck edges and center front.
Looking at the design pictures, I believe the 9” measurement comes from the beginning of the established pattern at yoke front, not from the cowl / collar join.

Recommendation:
for the look of the design pictures, work the collar for 5” from the join, larger needles.
Change to smaller needles and commence patt est to 9” total from center front.

Fit:
appreciate the detail notes others have on their project pages on ease and length of the main section.

Yarn:
am impressed with this yarn.
I ordered it a couple years ago for this design, sight unseen and am not disappointed in the least. There’s been a knot in a couple skeins, but have been able to work around that.

Swatch:
8” x 8” swatch was exactly on gauge, no shrinking upon machine wash / dry. A miracle.

Adjustments:
Hem
worked patterned hem section to 5” front and back.
added 4” to main section, which required about 2 more sk.

Sleeves
worked sleeves bottom up, casting on stitch count two sizes down, otherwise, sleeves would have been way too big at the wrist.
increased sleeves two st every 4 r to length.
worked a slightly shaped sleeve cap.

Cowl / Collar
worked US 8 for 5” of knitted on cowl / collar, measuring from the join row, then changed to US 7 for two more inches.