Engine dies, but turn the key off and back on it fires right back up

Because the CAP and CAS advances used a fast and long primary advance. They did this to get timing where it needed to be for power and economy while running late timing at idle for more complete burn of HC and reduction of CO.
By shortening the slot on the inside like Rockable did here, then its pretty much a pre-CAP advance. Everything will work as it should without changing springs. Small adjustments on the start can be done by adjusting the spring perches.
I think how and why is pretty well illustrated with Rockable (360 Tune Up) and further discussed with Mullinax.