This didn’t work so great. (I had a cover while they cooked.)
I used 3 eggs and 2 cups of dashi. 170 for over an hour and it wouldn’t set. I did a control batch on the stove for 6 minutes and those came out well. I ended up moving the sous vide bowls to the stove top to finish.
Aside: The fishmonger at the farmers market was really happy I was making chawanmushi with his scallops, and found me two perfect ones.