I got your mail, but prefer to respond here.
First thing off my chest, I am not the manufacturer, but Dutch dealer/imporeter/exporter.

Higher octane than the required 95 octane leadfree (european octane) does not bring extra power. (that be ~90 US octane)
The high octaine additives slow down the combustion flame front sufficiently to avoid pinging (knock) If there is no knock, extra additives to raise octane rating, though they harm the engine not, are a waste of money.
In racing engines, compression ratios are much higher to get the ultimate power from the engine.

The MVVS 116, though very powerful, is not a racing engine. If it were, it would have forged and shotpeened pistons, should turn at least 10000 rpm, devellop 18 horsepower, and require tuned pipes and a prop rpm reduction gearbox to make good use of all that extra power.
As it is, The engine is capable of turning a 32x10 prop at 5200 rpm without reduction. These are hardly racing rpm, and requires very different engine tuning.