At the top of the yoke, I knit one round even so that I could close up all the gaps from the short rows (I did Japanese short rows instead of wrap-and-turns). If you don’t, you’ll have some gaps (or wraps) to work when you try to kitchener the underarm stitches.
I modified this to have short sleeves. I determined the total number of stitches the sleeves should have after all the increases in the pattern are done (60 sts for my size) and cast on that number using the largest needles. After 2” of 1x1 ribbing, I transitioned to stockinette and knit till the desired length.
When doing the sleeve cap shaping, pay careful attention to the directions for decreases. You are doing sssk, not ssk, so you’ll be decreasing by 2 stitches at a time in places. It would have been helpful to highlight this in the Notes for the pattern.
I love this yarn but this particular color released a lot of dye during blocking!