Dirty Air, are these figures based on 100% VE?
I think they're bogus numbers, myself. I set out to do the same thing! Point of fact, I have an assembled short block that is coming back apart because all the local stations here dropped the E85 fuel.

Had a fuel tank to be installed in my truck and everything for the lake!
So, back to square, well, not quite one, but pistons have to be changed, cylinders matched, and rebalance the whole friggin thing to run on AVgas........

And NOW I threw a 10-71 at it............

BUT, Proppy and I explored this pretty extensively about a year ago which is when I pulled the trigger on an 10.5:1 initial compression engine to run around 15 or so PSI boost (assuming a 20% overdriven 6-71). I think the final compression came out about 22:1 or so. Very mild,perfectly fine with E-85, ethanol or methanol in a blown application. I was urged to go to 12-13:1, and toss even more boost at it, where I started looking for a GOOD 10-12-71. I have another 10-71, but nothing like this Mooneyham I just got, and I could never replicate it for what I paid for it.
Alas, and I have to say, he has the right to say "I told you so", Nordie warned me against this endeavor. Just not gonna happen or practical in any way shape or form unless you're willing to go to the ends of the earth to be the fastest out there.
Just random thinking out loud.........And I think, Superchargers are WAYYYYYY different than turbochargers are on the stuff. Turbochargers have no real way to take direct advantage of the cooling/evaporation effects of the fuel. They will to an extent, but not nearly the way a blower engine benefits, and thus, final C/R needs to be taken cautiously using E85 and Blower numbers on a turbo application.
Ray