I'm in the same boat with setting my timing.
Is your cold advance holding the linkage, or is it just really close?
Mine is dying on return to idle......brain moment for me.....maybe I need to adj mine to where it will touch at idle so that it does not snap back to far.
May I ask where and how much you are getting a Ferret for?
I can't get anything till the end of the year but I might be able to split the price and share it with fellow member seawalkersee.