Two things to keep in mind: first, zucchini shrinks when cooking. Just because there's a layer covering the entire bottom of the basket, it won't look like enough 20 minutes from now. Cut some more.
Second: keep an eye on things and don't trust what the knob on your burners say. The basket straddled the center and right burner, and both were between Medium and Low, closer to low. Everything looked good, so I ran inside a few minutes to work on salad. I was gone about 5 minutes when I came back and found the those slices over the center burner turning brown and smoking a little. Another reason to cook extra.
The stuff that didn't burn came out okay. I just wish I'd made more.
I also baked some plain Idaho potatoes. Next time, those will have to be spiced up a little.