Not much of an opinion as such from here Col . . .
. . . But, the practice on twin cyl camring mags was typically a ratio of Points Open to Closed period of 0.8 - so on a K2F it would mean points closed for 100° of rotation x 2, open for 80° x 2. On a 4 spark per rev mag those figures would be halved. On a single, much more points open time - as the coil charges up fully in the 100° points closed sort of arc of movement.
Camrings should offer the right ratio if the points gaps are set correctly, and while it might be recommended to focus on the dwell more than the gap on some distributors, not I think a good plan with mags as a big gap causes wear on the contact breaker and a small one risks arcing.
A small points gap will increase the dwell a bit, and a large one reduce it, as the points open earlier with big gaps. Wear will also be a factor probably.
I haven't ever tried to measure the effect of reduced or increased dwell on HT voltage with a mag. Maybe someone has?
The two priorities are that the gaps should be reasonably close to equal (within a couple of thou), and above all that the firing interval is as close as you can get it.
I have only ever measured the ratio (just using a rotary table) as an incidental activity when faced with worn camrings that need tweaking to get even firing. I haven't noticed a performance penalty as a consequence of grinding the cam lobes a tad. You could probably measure your dwell with a degree disc on the spindle and something to tell you when the points open . . . If you wanted!
