If you have an inverter genny (like yours) you can probably get away with it. A contractor style... definitely taking a chance as the power fluctuates during startup/shutdown.
I try to to remember to flip the main breaker when I start the generator, sometimes I do, sometimes I don't. Haven't had any problems over 10 years. Usually when I start the generator the only thing on is the converter and a few lights.
Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD 4dr short bed Duramax w/allison
Reese Fifth Airborne air ride king pin coupler with Sidewinder