Things to do with making knee socks on a Bro Bulky

My brother wants some knee length thick socks. I have a borrowed Bulky KH230+ribber and some 12ply.

12ply:
Pin Co 56 sts
cuff = 24 rows T6. Relatch
Leg: T5 RC60 -2 ev 4R to 40sts, RC116 → to 224RC
Rotate before 225 BACK to MB. (no hold on ribber)
Heel: wrap down to 6, then back. RC000
Feet: T5 to RC 66
Toe: every: 3rd round x 2; 2nd x 3; 1 x to 8 sts.

First pair I did I handknitted the cuff. I didn't want to have a seam down the back. This was OK, but I thought I'd try to see if I could knit circular and drop down relatch, how hard would that be?

First experiment was to knit them at T3, -2MT, which wasy way too tight, I tried T6, +1MT,  OK, but T5 on the last two pair worked the best.