I gave up on VP SEF in my saws a few years back. I had to retune all my saws because they ran super rich and if you put pump gas in they were on the lethal edge of lean. If you are going to go with VP I suggest sticking with it and try not to go back to pump gas unless you have too. I will probably give VP fuel another shot here this year and see if it has improved.
That's not a flaw in the fuel. It's just the nature of the fuel. I realize that SEF94 isn't race gas, but race gas runs WAY richer than pump gas. It's just part of it. For that matter pure gasoline runs richer than E10 pump gas.