Sounds like a fun truck.
You may think the fuel lines are OK with ethanol - 90-95% of them are. (By “fuel lines” I mean all lines and gaskets exposed to fuel) - many of these minor hoses work ok - but watch the assumption that “it can’t be this $5 hose”.
Many of the materials were not thoroughly re-tested for modern fuel mixtures - they did some accelerated testing, which is nominally OK. But if your friends start having weird engine management problems - look at the unimportant little hoses first. Starting at 100K miles.
Fuel pumps and carbs - are usually well tested - as they are “important”. Its the little hoses and seals - like related to low temp idle sensor, etc.
As an aside - anyone discussing how dysfunctional our society has become - when archaelogists look back - they will see that we are burning food (ethanol) just to make our cars run. Very Easter Island.
You’re right- the little o-rings and what not dissolve into black glue when not ethanol-ready.
There is a school of thought ( grass-fed cattle) that we shouldn’t be feeding corn to cattle; it’s unnatural.
But, the corn raised for feeding cattle isn’t what humans eat, anyway (in this country, at least). What goes into tortillas and corn flakes is not the genetically-modified feed corn that was diverted into the ethanol stream.
Wasn’t too many years ago (10 maybe) when corn was selling here for $1.80 a bushel, barely what it took to produce. Now they’re getting $3.50- $4.00 a bushel and can pay the bills.