I needed to go up to 6mm for gauge with this yarn, and knit with practically no tension.
The yarn has a thin elastane thread, which makes it really stretchy. When knitting, the yarn will stretch with any tension, then contract when it comes off the needles. You need to treat it gently, a bit like knitting with Nutiden. Slow and meditative…

I’ve used a little over 50g so far, and am 5” down from the armholes.It’s really light and fluffy.

Body and one sleeve weighs 159g.

I forgot to weigh it before adding the pockets, but the total weight, finished, is 193g

I made 2 pockets, in the same broken rib as the body, and knitted the ribbing at the top to match the hem ribbing.
Mattress stitching them on was challenging with black, fuzzy yarn… I used a daylight bulb and my strongest reading glasses. It took a while…

Measurements, unblocked:
Bust, 39” (not including the 5” overlap at the front)
Length, from bottom of the collar at the back, to hem, 25.5”
Underarm, 18.5”
Measurements, blocked:
Bust, 39” (not including the 5” overlap at the front)
Length, from bottom of the collar at the back, to hem, 26.5”
Underarm, 18.5”

I’m so happy with it!