There have been long term e85 tests on Walbro 255's with no issues, but then the 400L fails within a few months. It's the reason they released the e85 version.
I have been running my pair of Walbro 255's for nearly 4 years on e85, daily driven, without a problem so you would be fine.
Remember all fuel system components are designed ethanol safe these days as unleaded is 10% ethanol anyway.