I’m using a standard 4ply/fingering yarn for gauge. I also tried swatching with a heavier, sport weight @ 350m/100g, but row gauge was off, and I knew I’d have issues with the armhole depth being too long if I used it.
Row gauge is important with this type of raglan construction, unless you modify the increases.
Don’t miss out swatching, and make sure you soak and block your swatch to size. It could save you a lot of problems later on. The ribbed body stretches a lot when blocked…mine grew from 30” to 40”, and I could’ve pinned it wider if I’d wanted to.

Knitted size 2 with a couple of small mods:

I left out the last 3 rounds before the sleeve/body split, as it was already the right length after the last increase.
I only did 3 rounds of plain knit before binding off the neck. I tried 7 (as per pattern), but the roll looked too bulky for my preference, so I took out the last 4 and am really happy with it.
I did 6 knit rounds on the sleeves and body hem (rather than 7).

For the bind off, I was concerned that a knit bind off on 2.75mm might be too tight, so I used the Icelandic Bind Off on the hem, for stretch. It’s fine for the body, but I don’t think it was really necessary. It was too loose when I tried it on the neck, so I just used a knit bind off on that, and the sleeves. They’re both fine, and not tight at all…but my yarn was quite stretchy (due to being s/w).
https://verypink.com/2013/09/18/icelandic-bind-off/

My arms are long, and I usually need to lengthen the sleeves on most patterns. Even so, I had no wiggle room with the pattern, as the last decrease comes straight before the start of the cuff. If you need to modify the arm length, I would suggest making the increases every 18th or 19th round, rather than every 20th. Then there would be some (spare) rounds for adjustment after the last decrease.

Measurements, after blocking:
Bust, 39”
Length, from bottom of collar to hem, at the back, 22”
Inside Sleeve, 18.5”

I love the way the neck fits. Those clever decreases at the back really give it a lovely shape…

The finished sweater is stylish, comfy, and classy. I’m sure I’ll make another one (sometime!).

And, I should mention, that’s it’s very easy and well written with clear instructions.