Unless you're rich and have lots of spare motors lying around. I would set your motor up once and forget about it unless there is a need to touch it (eg, massive humidity changes, etc.)
I've seen people tweaking and tuning to get the last bit out of the motor, using a tach, model up-and-down, you name it. Take off and can't fly or just do high-speed passes the length of the field and annoy the heck out of everyone.
I've seen the pros (the really competitive flyers, not the wannabe's) start their engines, check the settings (ususally one up or down to check lean-out), MAYBE a quick flash of the tach, touch the neddle valve (click-click), taxi out and go flying. Land, fuel up, and go out again without touching the engine.
Their engines are not maxed out but running solidly and putting out good power. If you are running your motor at its absolute limit, you're flying with the wrong motor and/or prop.