Interesting statements in there about products and findings. News to me (and contrary to my own experience) they found ethanol doesn't particularly affect long term stability.

Also news to me -- that copper and zinc cause phase separation and cloudy gas within 30-60 days. This is something I had attributed to ethanol but perhaps it's copper leeching from brass fuel fittings or zinc leeching from a fuel filter housing? (I don't know where to get outboard fuel line fittings that don't contain brass.)