Spark plug gap is dependent on ignition system energy and cylinder compression. I prefer a slightly larger gap but not too large as to cause misfiring.
A slightly larger gap may increase spark intensity. It takes more of a voltage build up in the secondary windings of the ignition coil to produce a higher voltage strong enuff to jump the larger gap, but the spark duration is shorter(kinda the same as a CDI system), and the larger gap exposes more of the a/f molecules to that spark creating a larger kernel of flame thus better combustion.
.006" in plug gap is nothing on a stock engine and I have found over the years no consequences.I installed a DynaTek CDI system on my Vaquero and gapped the plugs at .050", and when that spark jumped the gap with the plug grounded on the engine...IT SANG!!! Same sound the MSD ignitions on the 4 cylinder skoots I have werked with.
a .006" increase in plug gap may not produce any measurable or noticeable benefit, but it goes in a positive direction in how all this stuff werks together.