I'm going to share my personal experience with 50/50 blend of R85 and 93. background...5+ yr old
Aeroquip SS braided rubber hose, Aeromotive Eliminator in-tank pump with their SS pre-filter, Aeromotive 40 micron SS post filter, GM Flex fuel sensor "Y'd" into return line, 120 injectors, FAST XFI, new Ricks SS tank. Had E85 in tank for less than a year. Car started backfire under acceleration, then wouldn't accelerate, finally wouldn't idle. Long story short, found both fuel filters plugged up, injector baskets plugged up, and several injectors not operating. dropped tank and found black/ brown particles everywhere.
Removed E85 blend out of tank, injectors cleaned by Chuck, replaced inline filter element with 10 micron paper element three times to get all the rubber remnants out and everything is great. FWIW, the stuff that I found will pass through a 40 micron filter and some will pass through the 5 micron fuel injector inlet basket. Will go back to E85 once I switch fuel lines to Teflon lined hose.
Conrad