My waist size is 31, therefore I got the 702 in 30, following the size chart on the Blueowl website. I gave them a hot soak when I got them and an other one after three weeks. Haven't washed them yet and am only wearing them around the house, as they are too heavy for the warm late summer weather. Still hope they will stretch a tiny bit.
At the same time, I bought a pair of Japan Blue tapered vintage in size 29 and they are far more comfortable.