Oregon cam nailed it!!!
There is a recent 34 min you tube video by Cattle Dog Garage. Sorry, do not know how to link it.
He confirms D. Vizard's 128 rule, with lots of dyno tests & technical explanations. He also confirms DVs claim that if you want a smoother idle/more low end, you do NOT widen the LSA, you shorten the duration.
Anybody contemplating getting a cam ground should watch it....