That is correct. The HEI will require the original advance unit.No advance with the HEI as is.
I'm using the HEI to get a feel for it's signal levels etc because I've not played with one before and it was less then $10 . The cool thing about the HEI is it will work with the stock points.
I have a late model Gonzo box coming tomorrow to try out because the interior shots @LanzSilva posted look different from the early boxes .