This pattern was so fun to knit! The description was easy to follow, and includes a lot of tips, as for modifying sleeves and blocking.
I’m very happy with the fit of this sweater. I made only a few modifications (all are noted below), and mostly followed the pattern.
It was a pleasure to test for Stephanie!

My gauge for the yoke, washed:
My row gauge is 2 rows looser than in pattern. Stitch count is close to pattern.

My gauge, measured on body:
Unwashed, stockinette:
20 sts/ 30 rows.
Washed, stockinette:
20 sts/ 29 rows.
More about gauge for colorwork: see in notes below.

Yarn amount used total:
MC black: 341 g
C1 purple: 28 g
C2 white: 75 g
C3 grey: 113 g

Yarn amount used, details:
MC black: 341 g
(50+50+49+44+48+51+49)
(1) 50 g. 22 g used for neck/ start of yoke. Skein used up ca 3 cm from armhole.
(2) 50 g. Used up 12 cm/ 4.5 inches from armhole.
(3) 49 g. 1st sleeve continued, 12 g left before sleeve chart. 8 g left after chart (before decreases). Used up at cuff 6 cm length.
(4) 49 g. 5 g used for last 4 cm on the cuff (44 g left, 2nd sleeve started with these). Leftovers after sleeve chart rnd 2: 5 g unused.
(5) 49 g. Attached at 2nd sleeve cuff. 14 g used for cuff; 35 g left, used for hem rib later. 6 g left after hem rib (5 cm rib, 13 rnds), used for BO. (1 g left unused after BO)
(6) 51 g, attached at body 12 cm from armhole. Used up at 19.5 cm from armhole.
(7) 49 g. From 19.5 cm from armhole to 28 cm from armhole (all used).

C1 purple: 28 g
(14+17-3)
(1) 14 g. 7 g used for yoke chart rnds 1-7. (7 g left, used for 2nd sleeve chart)
(2) 52 g. Yoke chart rnds 54-59: 12 g used (40 g left). Sleeve no. 1: 5 g used (35 g left, unused).
Sleeve no. 2: leftovers from skein 1 used. (4-5 g used for 2nd sleeve; 3 g left unused at the end)

C2 white: 75 g
(48+27)
(1) 48 g. Used up at yoke chart rnd 42.
(2) 49 g. 16 g used for remaining body chart. (33 left). Sleeve no 1: 5 g used (28 g left). Sleeve no.2: 6 g used (22 g left at the end)

C3 grey: 113 g
(55+51+7)
(1) 55 g. Used up at yoke chart rnd 35.
(2) 51 g. 43 g used for remaining yoke chart. (8 g left, used for 2nd sleeve chart)
(3) 53 g. 7 g used for sleeve chart (1st sleeve), 46 g left (unused).
Sleeve no. 2: all leftovers from skein 2 used.

Sleeve decreases:
6 x in every 5th rnd.
5 x in every 4th rnd.
This means that I placed a marker in dec rnd (counts as 1st rnd), and then worked 4 (or 3) plain rnds after this dec rnd.
Sleeve length before chart (unwashed): 22.5 cm.
Sleeve length after finished chart(unwashed): 33 cm. (Washed, it did grow to 34 cm.)
I worked the cuff 10 cm long, so I can fold it up. I used a stretchy BO, alternating between k1 and p1 before knitting the 2 just made loops through the back loop.
Link to Stretchy BO tutorial by Very Pink.

Hem:
For the hem, I used another type of bind off. See in notes below (bottom note).