at one point in time fuel contained lead , the same concerns were voiced then. now fuel contains no lead. do you add upper valve lubricant to your non-lead based fuel? or do your valve guides suffer in silence?
agreed ethanol eats older seals , it is a relatively small modification to your vehicle to accept ethanol blended fuel , as adding upper valve lubricant is to accept non-lead based fuel. not to mention ethanol blended fuel is an option at this point.