Remove the drift pin holding the safety pin? in place. Take out the safety pin, turn it 180 degrees and mark it where the drift pin hole is. Then file a notch in the the safety pin so that when reinstalled the drift pin will hold it in place. Now the firing pin is locked in place. And it is reversible to return it to it's original configuration. Worked for me. Just be judicious in filing the safety pin to make sure it is held up as high as possible.
I always liked to carry a full size gun off duty way back when I was a Deputy. Like you said, it doesn't matter that much if the grip is longer so why not? I felt better with more grip in my hand, a bit more control of the gun.