It shouldn't. Several things to do to help the crank live a long life...
Get the primary balanced. Polaris doesn't do a good job of that.
Add the wide bearing kit to the PTO end to spread the force of the crank over a greater area. That can be spendy, and some places require the cases and the crank so they can ensure the case has not started to fail.
Add an engine plate. The plate stiffens things up a bit and helps keep the bottom end planted.
There are also push stops and torque links that can be installed so the engine stays square. That helps belt life more than crank life, though.
When I had my two 800 Edge sleds, there wasn't 2 MPH difference between the regular setting and the premium setting. It did seem peppier on the premium setting. I run 91 non-alcohol fuel.