B.B From what these learned studies show, there is a variation in the combustion process between every engine stroke or cycle. Just like the gas flame on your stove flickers and wavers slightly, but still burns well enough to boil the kettle, it hardly matters. Likewise our engines run well enough, but as researchers investigating combustion of hydrocarbons at the molecular level find, sure enough in the real world nothing's perfect and there are variations. It don't need some genius to tell them that.
Whether this is of any consequence barely matters, as we ride our bikes a changing throttle setting, gradient, spark intensity, fuel flow etc are all additional variables, let alone the fuel itself which may contain hydrocarbons of varying chain lengths, water, organic material etc, all contributing to a less than 100% perfect and identical combustion on every stroke. If I'm screwing it on down the white line I tend to concern myself with safely completing the manoeuvre, and I'm well happy that it keeps going, imperfect combustion and all.
All storage tanks will accumulate water to a degree, this enters as water vapour which condenses, or by direct water entry through leaking or missing caps etc. The water in the fuel provides opportunity for anaerobic bacterial growth.
Previous posts and threads discussed the merits of adding water directly to ethanol containing fuel, then decanting off the upper petroleum fraction to leave the ethanol in the aqueous lower layer. Most fuel tanks draw from slightly above the bottom of the tank, above the level of contaminants. Our gravity fed arrangement would benefit from a water trap/filter below the carb. I'm thinking transparent inline jobbies at the lowest point of the fuel line. Certainly easier than messing with barrels, funnels and the inevitable spill.
As for additives, I reckon its the snake oil salesman's next prospect.
Swarfy.