Staying out of the p155ing contest, this is how I understand fine wires and the combustion process.
0 to 100 microseconds after 'spark' begins the primary field collapses due to no longer receiving voltage and the secondary field begins discharging. As it is discharging, it is ionizing the fluid in between the center and ground electrode of the spark plug (the air/fuel mix). As the ion fields grow out from the center and ground electrodes, they eventually meet, and an ion path is formed. Essentially this is a wire in the air made out of ionized air particles, like a mini lighting bolt.
This is the point where voltage spikes. It takes a lot of electrical pressure (aka voltage) to create the ion path, up to 40,000v depending on the ignition system design. THIS is where spark plug gap plays the biggest role. The longer the distance between the electrodes, the more voltage is needed to create the ion path (i.e from the coil)
Once the ion path is created, the voltage drops. Combustion still has not happened yet.
After the ion path is formed, it begins to transfer all of that energy stored in the secondary coil. THIS is where combustion begins. As the energy is transferred between the electrodes, some of the air/fuel mixture is ignited. The combustion event is VERY small at this point (the "little buddy flame"). At this point, there is not much energy, so any that is absorbed means there is that much less energy to multiply out into the rest of the cylinder. This effect is known as quenching.
This quenching action is where fine wire plugs plugs win. There is less material to cause quenching, therefore, more energy to get out into the cylinder. This gives a more even burn. With LOP and high EGR strategies, low quenching becomes VERY important.
This quenching effect is also the reason gap is important. The bigger the gap, the farther away the 'little buddy flame' is away from the electrodes, therefore less quenching occurs.
At the point the energy from the secondary coil is released into the surrounding fuel/air mix (this point is the 'holy grail' for a good plug, how efficiently that energy is transferred), combustion occurs in the fuel/air mix and the spark plug is now irrelevant (although it's effects are not).
New plugs should be gapped correctly already from the factory these days, but any uneven burn across cylinders will eventually result in the gaps increasing unevenly as well with resultant issues. Replace them if you can't regap them (i.e fine wire plugs..they are too delicate)