My take is, try it and see. Just make sure your distance and sight picture are as consistent as possible.
Shooting from a sandbag rest will give you a true picture of what the 709 is doing in terms of POI while taking the shooter out of the equation. Without the rest, you are just adjusting your sights to your shooting for that particular day.Yes, this is a "your mileage may vary" case.
I would caution you to do these sight adjustments using a benchrest position, and make sure you are using just the pad of your finger on the trigger.