I've not tried it in a saw yet. I've been meaning to sometime. The carbs I have drilled bigger are too big for methanol.
If you can get e free gas easily, and very minimal cost increase, even I'm all for that. A saw uses a tiny amount of gas. The best practice with a saw is to empty the tank, then run the carb dry. Because it's easy. Even e10 will store for a couple months no issues. All modern saws are designed for using e10. If you've modded a saw, you should understand it's fuel requirements.
Motor trend had a long term Silverado with said 5.3. They did tests for mpg, dyno, and acceleration tests on e10 vs e85. Your mpg drop is quite a bit more than they found, but YMMV. Literally. 2014 GMC Sierra Denali 1500 4WD Crew Cab Update 4 - Motor Trend I'm starting to lean toward buying a f150 with the 5.0, as that is fords flex fuel motor in f150s. There's a station very close to me that sells e85 for 1.59 a gallon, all the time. It doesn't move from that price. Meanwhile, regular e10 is at 2.25 or so a gallon. I'll take a 30% drop in fuel costs for only a 13% drop in mpg any day.
Our 2000 Taurus had the 3.0 (2 valve) flex fuel in it. I ran exactly 1 tank of E85 through it. The fuel was only $0.10 less /gall and the fuel mileage dropped 20%....ahhh, nope, not gonna do it. If we had $1.59 E85 then maybe, as long as I didn't have to drive out of my way for it.
If you baby the truck, it might stay up around 11MPG on E85. But if you use the truck to do anything more than haul your own carcass, fuel mileage is non-existent. I'd almost believe I could push it down into gallons per mile territory trailering at near capacity.