Unless they make small engine carburetors out of something different than what they make full sized car engine carbs out of, I don't understand how it would get any more destroyed than say the quadrajet on my old chevy truck.
Also, alcohol in carbed applications is less a problem than in fuel injected applications. carb you can adjust the richness screw to compensate for the introduction of higher levels of alcohol. engine will run cooler with more alcohol. The big problem comes in fuel injected applications, which use an O2 sensor in the exhaust stream to determine the burned air/fuel ratio. Cooler exhaust is indicative of an overly rich condition, which the engine control module attempts to correct by leaning the crap out of the fuel mixture. this in turn leads to detonation, which triggers the knock sensor to retard the crap out of the timing. eventually, the ECM quits listening to the O2 sensor, and replaces it with a dummy value, that provides a lot less power, poor fuel economy, but will prevent the engine from destroying itself.
Carbs don't do that, and unless the carbs on these engines are made of cotton candy, alcohol isn't going to magically destroy it. Seals get old and brittle on their own from years of service, and eventually all carbs need a rebuild to install new seals. They design these with the idea that they're going to be full of caustic unstable flammable liquids