Not also, is just bcs 5,4 come from factory as a flexfuel, but it doesnt' mean you can't use E85 in others engines.
I would like to know where you find enabled/disabled E85 in Forscan ?
About components, some old plastic pipe may not apreciate E85, but now standard fuel has a part of ethanol, so no major problem for engine built after 2010 and perhaps before...
About injectors, it's a question of size, you need injector able debit a lot, what we already have on Raptor I guess ^^
All cars with twin sensor exaust catalyst manage E85 adding alone , the sensors send informations of the combustion to say to the engine more or less air/gas. (and the risk with ethanol (and no modification) is to have a car wich is not able to do that correctly and run with a too poor mixed, in fact, too much air, or not enough gas)
I use 50% of ethanol (sometime more) in mine since the beginning (almost 2 years now) without any modification and any problem...
To conclude, I would say that even if I had a 100% flexfuel engine, I wouldn't use as it just bcs E85 is a "dry gas" and run whith it all the time could make some dammage on inlet valkve for exemple ... So I think have sometimes a mixed is a good thing between lubrification and deslagging...
To finish, I have noticed that more I have ethanol in tank, more power I have, and off course, less mileage I have, this last point are well known by E85 users