I took Shelly’s advice and clipped out the temporary stitches in the cast on (see those here) before I knit too far along. This way if the cast on was bad I wouldn’t have put a lot of work into it and starting over wouldn’t be as heartbreaking. Thanks for the advice Shelly! Happily, the cast on hem is just fine, you can see my transitional section from 3×1 rib to 2×2 rib here.
I’ve done about 8 inches and so far it’s been going pretty quickly.