Rob, if engine use light flywheel, or high CR, or it is really cold or weak battery or combination of these, ECU with so simple trigger have no any capabilities to give precise advance on low crank speeds, because huge speed variations during this 60degries.
I believe VEMS use last possible tooth for advance calculation wit multitooth wheels. And why not use this feature?
But one trigger tooth per event I want to consider as old school.
In Latvia climate it is not usable - you can stay without car on cold winter morning because of too advanced spark event. No one OE no more use this type of triggering. And it was also rarity in 80-s.
E.g look at Subaru 6 teeth trigger wheel. They use ~60deg tooth for advance calculation on running engine, but ~5deg tooth for cranking. Same with BOSCH hall sensors in distributors: one edge for running, other for cranking...
Gints