10% Ethanol will not start……no fire??

I can't say as I agree with you guys.
My 367 has NEVER, since 1999, run anything but 87E10, and it turns 93 in the Eighth, so is no slouch.
Yes after a week or so, the E10 has turned thicker and the car doesn't like to start right up (no choke), but it's a double pumper so, I just fill the intake with that swill and away it goes.
To combat that, I always mix in some stabilizer at every fill-up. I found a place under my hood to store about 500mls of stabilized gas in a sealed container. If I have trouble, I just dribble a lil into the intake. The gas in the tank with stabilizer in it, runs just fine.
Honestly, IDK what all the hullabaloo is about.

Well I suppose, having up to 185psi CCP (cranking cylinder pressure) might have something to do with it......

If I had to guess, I'd say your Transfer-slot exposure under the primary throttles, may be lacking. Crank up the idle-speed and see what happens. If it works, and if the warmed-up idle-speed is too high, retard the Idle-Timing to slow it down.