With the solenoid activated, the VES valves are either in the low position or the high position. They are not variable. With the solenoid out of the picture, the valves open a little sooner and are more variable, transitioning with RPM from low to high. Polaris added the solenoid to help with exhaust emissions, not for any additional power. It shouldn't make any difference in fuel consumption either way. It's easy to try and easy to put back if it's not helpful or you don't like the way it works. Your call.
Like RJ said, your rpm at 9000 is out of the powerband. I would at least change the weights and spring in the primary when you ride the high country.