I'll be interested to see how the tape works out. It doesn't seem like adding insulation to the motor is the way to go. I was told by a mechanical engineer at work that the motor is designed to dump most of its heat through the machined front face. You really need to get rid of heat--not hold it in. The screw will still be conducting heat into the extruder block. I think the hot screw is primarily what causes the extrusion to yield and let it through. Maybe I'm wrong. Let us know.

I have been doing some test prints with the Makerfarm knob. I'll upload some videos when I'm done. I noticed that the design of the knob requires the printer to make a last pass around each layer, filling in a small gap at the tip of each ridge on the knob. This requires an retract/advance cycle as it moves over each gap in the knob perimeter. If your retraction is having any trouble at all, you'll get gobs of plastic built up around the sides of the knob.