Stihl offers their own version of TruFuel and they call it
Stihl MotoMix,
Husqvarna offers one too.. With Stihl if you purchase 1 gallon of it, at the time you purchase the equipment, Stihl will
double the warranty. Pretty much a no-brainer. There are many versions of a TruFuel type product out there but they are all very expensive.......
The clue in this is that gasoline is really very stable IF it is sealed from air and water. I've kept samples in bottles for years as controls for experiments, and there is generally no change. The same is generally true of diesel. (There are minor exceptions in both cases, but not really with US fuels.)
Thus the key is to limit breathing. Dependably closing vents on small outboards really helps. Vent filters help (they reduce both water absorption and oxygen transfer). These have been used in industry for 50 years.
Another factor is corrosion products, specifically copper and zinc. Read any diesel engine maker recommendations for stand-by generators and they forbid copper, zinc, and their alloys. I learned 30 years ago to never spec copper or zinc in high temperature systems, where the effect is even greater. Not only can corrosion products clog jets, they also catalyze deterioration. Take 3 small glass jars. Place a few drops of water in each and fill with e10 (the water will dissolve--this represents normal absorption). Fill the other with e10. Place a penny in 2 of them. Come back in 6 months and observe the varnish in the one with water. (I've run this experiment and similar ones, with many variations.) The lesson is that the water does NOT have to form free layer. Any amount hurts in e10 because the ethanol allows mobility of corrosive ions.
If you can eliminate water that helps, but this is impossible in a carb. But you can stop the copper and aluminum catalyzed polymerization with a good additive.