Beautiful pattern.
I used a 4mm hook instead of the suggested 5.5mm, I like the finer stitches better.
I made an adjustment to the beginning and end of the pattern so it looks more ‘rounded off’.
-leave a 60 cm tail at the start
-work in the back of the starting chain
-follow row 1 but skip 3ch (instead of 2) and dc into next 6 ch (instead of 8)
-then work row 11
-then work row 2-11 etc (as the pattern)
-let row 9 be your ending row (instead of row 8)
-after 15 patterns ending with row 9 in which instead of shells you work 2 dc
-ch3,sc in ch2 space, ch3, sk 1dc, sc in next dc, ch3, sk 2dc, sc in next dc, ch3, sk 1dc, sc in ch2 space, ch3, slipstitch in top of ch3 of previous row.
-back to the beginning; work with you 60 cm tail you left there and work the same adjustment at this end of your scarf.