As I understand it one of the benefits of California having stricter air pollution standards is that they started messing with alcohol in the mid-80s and all the major US manufacturers, reluctant to have two separate sets of gaskets and hoses, shifted entirely to materials that are compatible with alcohol.

Check your owners manual.

If your genny is old enough to have components incompatible with alcohol the odds are it could do with an overhaul and new gaskets, filters and hoses.

There are other issues with alcohol. One of them has to do with E-10 fuel stored in gas tanks for a long time may pull water out of the atmosphere. Which may cause fuel line gelling and freezing or sludge formation in the bottom of the tank.

The other issue has to do with vehicles that have used non-E-10 gas for a long time. In straight, non-alcohol gasoline water, and water soluble crud, tends to settle to the bottom of the tank and remain safely out of the way. This is why sugar in the gas tank doesn't work. Sugar isn't soluble in gasoline so it sinks to the bottom instead of dissolving.

The problem rolls around when you have water soluble crud in the bottom of the tank, and perhaps a little sugar, and you fill up with E-10 gas. Suddenly all that crud which was safely resting on the bottom dissolves in the alcohol and gets sucked into the fuel system. It can cause the fuel filter/s to clog and other issues. Over time the crud that collected over a long time gets run through the system so, in the end, the tank ends up cleaner. But the the initial transition from straight-gas to E-10 can cause problems.