IIRC further discussion on this topic never came up with a wholly satisfactory answer as to why the plugs performed the opposite way round in real life, except perhaps that on the test the ECU hadn't fully adapted.
None of the performance tuners recommend changing the gap, so I see no reason to do so.
well, the more boost you have, the harder it is for the spark to jump, possibly causing premature coil failure... I was reading an artilce about a twin blown hemi V8, that needed a fairly large coil amp so that it would actually cause a spark at such high pressure in the cylinders.
If the plug is gapped too wide, you get retarded timing, and more strain on the coil(s), and a short spark interval (causing loss of power, from incomplete burn), (under the same conditions) a gap that is too close will give an advanced spark, with a longer spark interval, possibly gaining power, at risk of detonation.
However, a trionic ECU as i understand it, should detect the point of ignition, and adjust timing to suit (although full potential of the DI system will not be utilised, as it can only retard the spark so far)
I don't know if my ramblings have been any use, but there thay are
Trionic also adjusts it's ignition energy based on boost pressure. This is so that it can still ignite the mixture at full boost easily, but also not wear out the coils with a super-hot spark when just cruising.
When "tuning" the engine to higher power, it should automatically adjust to some extent. Because of better exhaust scavenging and intercooling with upgraded parts, it may be harder to ignite the mixture, so in some cases it may be necessary to slightly close the plug gap.
You don't have to be mis-firing to be losing power from insufficient spark-energy or excessive plug-gap. But ... there's also no reason to run out and gap your plugs as small as possible either ... more than likely, stock is fine.
Things like the Ionization Gap Sensor system and Water Injection make the plug gap even harder to compute. Generally as long as the plug is similar in shape to stock, and not drastically altered, the IGS system will be happy enough. And water injection will usually just need a slight reduction.