I followed the pattern through round 3. Instead of round 4, since I didn’t want to chase down elastic thread, I did some shaping.

round 4: I did dc4, hdc3, sc around to last 7 sts, hdc3, dc4.
round 5: sc2tog to side, (maybe 3?), sc around to other side and repeat the decreases.

It occurs to me I might have used a clear plastic band for row 4.