For a lot (most?) of my engines the recommended fuel is E0 or leaded. That doesn't change my experience with E10.
At some point in the increasing eth ratio I would expect carbureted engines will need some mixture adjustment, but checking plugs, jets and mixture screws is nothing new. Modern fuel injected vehicles should be able to make their own adjustments.
Here's an E40 burning skidoo that BRP is quite proud of.
2012 Clean Snowmobile Challenge Winners Chose Ski-Doo | Ski-Doo On Track
BRP had nothing to do with that, other than build the stock sled ,equipped with a 600ACE Rotax engine which IT recommends not be operated on fuel containing more than a 10% ratio of ethanol to gasoline. Kudos to the students at Clarkson for their modifications;question being(how long will that engine operate and at what level of efficiency at this concentration?)