You will be fine with fuels that add a very small percentage of ethanol in, that won't do anything really. I was running 50/50 and now I'm running Full E85(100%) so it was a given that this was going to happen with the stock white Fuel injector Seals. Once the Viton are in, I should be able to never worry about them again.
E85 is only 85% ethanol at max... they are usually less than 85% in reality...especially on winter blends which can be as low as 70% ethanol.
Only people having issues with the seals have been guys running E47 and E85. I would imagine that GM has tested the seals in the 93 octane with 10% ethanol and not had noticable issues... however it is a seal, and they can wear out eventually. Ethanol just speeds up that issue.
I am still waiting for the rubber fuel lines/socks in the tank to start failing, or the pump itself. Not sure what fuel pump is in the tank or if it is rated for E85 use. Mose OE applications are not rated for ethanol unless they are flex fuel vehicles, however it all depends what parts bin sending unit is in the kappa
For reference:
"Top tier" premium pump gas = no ethanol
Premium pump gas = up to 10% ethanol
E47 (mixing E85 and 93) = 40-47% ethanol
E85 at the pump = 70-85% ethanol depending on blend and time of year
E98 = 98% ethanol and only water is added to the fuel to make it legal to sell.
E100 is 100% ethanol which is illegal for sale unless it is diluted to E98