I did not even consider a ground clearance switch when I stared doing my panel.
It was only after flying a king air 250 that had a ground clearance switch, then I needed one for my Commander.
Now I press the ground clearance switch and the airplane stays quiet and just my 750 powers up.
Typically I get my clearance several minutes before departure and prior to boarding passengers. Most of the times it doesnít matter but at other times you might get a surprise change in your routing or they have a delaying in picking up the clearance.
I donít like having passengers on board unless I know we can move.