Hi Daniel, I have never seen a shorted heater cartridge, but it's not impossible and they are relatively high current, so the effect would be fairly unpleasant and possibly expensive (new duet board).
So it is worth avoiding, use some resistors in your sensor circuit or some other more sophisticated electronic protection (not really my area of expertise).
If you can crack the challenge of an affordable, conductive build plate then you have a winning product on your hands. Imagine a kit, in it there is a conductive printing surface which connects to a small PCB providing some protection, a trigger output to go to your controller and nice LED's, there is also a wire to connect to your heater block. Neat yes?
Conductive PEI is available but scandalously expensive. However other conductive sheets that you can print onto such as polycarbonate (with appropriate sanding) might be worth pursuing. Indeed most of these things have quite high resistance so the risk from a short is probably lower. One such conductive PEI can also be used as a bed heater, now we are talking convenient, but very expensive at this point in time.
