Removed the element and confirmed visually that there was a burned out gap in the outer ring. Ordered new element from Appliance Parts Pros, after livechatting with them to confirm the part number.
The part arrived quickly—great turnaround service. I was a little confused by the wiring at first, because it is not exactly the same as the part I replaced.
There are three electrical tabs on the side of the element. One for the inner ring only, one for the outer ring only, and one that serves both rings. On the old part, a black jumper wire from the temperature probe was cold-pressed to the middle tab, which served both rings. On the new part, the tab that serves both rings is moved from the middle and the black jumper wire is replaced by a hard metal connection to the temperature probe.
So, one must inspect the old part and the new part to see which tab serves only the outer ring, and which tab serves only the inner ring, and connect the wires accordingly. It's a small difference, but getting it right it makes a difference. Otherwise the switch will be very confused, like I was when I started this process.
Altogether, good experience, top marks for Appliance Parts Pros, who delivered promptly, at a good price, and helped walk me through the installation process via livechat. I'll use them again.