Above talks about quenching action....
Nothing to do with combustion chamber quench.....
In electrical theory, there is a phenomenon called quenching; it refers to the fact that when a spark is generated from metal, the surrounding volume of cold metal tries to quench/absorb/ extinguish the newly generated spark. By reducing the volume of cold-er metal that could extinguish the spark, there is more chance the spark will stay 'lit'. Hence the benefit of fine wire Plat & Irid plugs; a side benefit is less arc over voltage, so a marginal ign system could fire a plat or irid plug.....but wouldn't fire a conventional plug.
As for plug gaps with P & I plugs, if the ign system uses a bal res, use a 0.045" gap. No bal res, run 0.060" gaps.