Richard Sohn
My take is that it is mostly snake oil; but could be beneficial if your plugs are subject to fouling. There is very likely very little additional power into the spark; but the available power is concentrated into a very much shorter time – instead of lighting up the spark for 30 millions of a second, it concentrates it into about a billionth of a second (using their numbers). Whether this is really advantageous to igniting the mixture; I don’t know, my guess is probably not.
However; doing that would definitely more likely fire a fouled plug. It is similar to holding a gap between the plug wire and the plug. I remember from way back when I was a kid and had an oil-burning Chevy that would foul plugs. Rigged about a 3/8” gap between the plug wire and the plugs, and it would run fine.
Al