Never done anything BUT shoot off-hand.
Back in my...almost every weekend shooting powder burning days. Both handguns and long guns, and a coupla short...long guns (bullpups!).
And now that I have a couple of PCP, springer, single pump, and C02, I'm still shooting offhand. I'd imagine that most PCP's and my single shot springer, along with my single pump "target" gun, they can shoot better than I can.
So...that said, why benchrest shoot ? "I"...need to be a good shot...NOT some bench full of crutches..! Just my opinion.
Mike