You could test your gas with kits that are available on the Internet. I test mine now. I know the gas in my local station is free of that crap. I plan to test other stations as well.
Any recommendations as to which kits work?
Costs of kits, supplies etc?
The test is pretty easy to do. Get a test tube or something similar you can see through. Add gasoline up to a mark, then add some water and shake. Any ethanol will mix with the water and separate from the gasoline. If after shaking, your gas line has lowered, that is how much ethanol blended with the water.
Ethanol is really hard on two stroke motors because it dilutes the effective ratio of the oil mixture. I overdose the oil by 10% or so to compensate. Not ideal because it will cause the engine to smoke and foul plugs.
For small four stroke engines, I always add sta-bil when I get the gas home. Unleaded gas starts to foul in as little as a week if not used. Also, 2-3 times per summer, I add a couple of ounces per gallon of Marvel Mystery Oil to a tank of gas. It will clean varnish off the jets and needle valves. A "liquid tuneup."