I got my heater put together today and installed.
I hope it works. I did it very similar to mrgpk's original post in this thread.
I found some foil lined heating/cooling duct insulation that was 12" wide instead of using strips of insulated tape. But most of the rest is similar. I drew out a template in my CAD program, plotted it out full size and cut it out.
The ZooMed heating cables must have changed some, as the heated portion is fairly long now. I only put a little over half of it inside the collector.
I had it plugged in for 3 hours and 20 minutes this evening, and didn't notice any temp rise. It actually dropped the same as another outside thermometer did. There was a chance of freezing rain or light snow, but that's not going to happen tonight. Have to wait to see how it works.