Modifications
I did duplicate stitching on the raglans, which is not a part of the pattern. I just held the yarn double and bottom up duplicate stitched all the knit stitches every second row in the raglans.

I am trying to figure out if the pullover feels a bit too short. It is exactly the length stated in the pattern for size S, but it turns out a little cropped on my body; it sits right at the upper part of my hips. Maybe I will take apart the ribbing on the body and knit a couple of rows to lengthen. I am not sure.

Update: I have separated the bottom ribbing from the body and have knitted 5 cm extra bottom up from the live stitches of the ribbing. Then grafted the pullover together with the newly knitted part.

About the yarn
It is lovely and easy to work with, although splitty. The fabric looks dense, but is light weight. It is soft, squishy and bouncy, making it a pleasure to knit with. I am looking forward to see how this holds up and how much it will pill. When first knit up the fabric looks really uneven, but it smooths out beautifully with blocking.

Beware! Before wet blocking I gave it a (gentle) spin cycle (1200 rounds/min) in the washing machine to remove excess water, but be careful! The entire sweater felted and I had to pull hard in all directions to get it back to its intended size and block it out to measurements. Will not do this next time with this yarn.