I've tried every type of coil and plug possible on the dyno back in the day. Nothing on the planet will make more power over an another, with one exception, in the four stroke Yamaha engine we found more power using the twin electrode EK plugs, and of course with mods of any type we would drop a size on the temp range. We've run the EK twin electrode style of plug in four-stroke big boost engines and stock engines. They always seem to make 3-4 HP or about 1 HP per cylinder. The reason is the flame kernal is super exposed to the charge you want to light off. I have not tried the new copycat high dollar Brisk and E3 type plugs, nor do I see the need.
I tried the waste of time Nology stuff when it came out and a bunch of supposed hi powered coils and wires. I was one of the first to use the MSD programable MC-4 pro-stock bike ignitions back in the day, and the features it had was very advanced for its time. The benefit of it was you could program timing in it over time, RPM, shift points, it had all sorts of hi-tech features built in, plus it provided multiple sparks over a few degrees of crank rotation, a real arc welder! But it had no added power over the ignition it replaced on the dyno. The advantage it provide was down track in reducing timing, keeping the engine alive and making more RPM down track than by not reducing timing. Found the four-stroke turbo provides lots of power with added timing advance, so just the opposite, but only to a point and depending on the time of year and temps being run in.
As long as the flame front is lit and the charge fires and does not misfire it will make power. The problem comes when a plug fouls or the ignition does not have the power to spark under high boost, which the winder seems to have no trouble with what so ever. Don't overthink the spark plug thing, they either spark or they don't, if you want a couple more HP try the EK plugs. The winder doesn't not even seem fussy to gap, which tells me the ignition is plenty up to par stock.
