I understand all that and wish I'd been beside you to watch. That way I'd be some actual help here. I use a sand bag for serious work because there's no substitute except for a machine rest. I have small bags and keep them in shape. I too have my hand under the forend as that's what we taught the troops. The wrist actually goes to the bag and the hand is on top. The rifle doesn't touch the bag. A sling for ironing out accuracy and perfect zeroing and then the practice off hand and other positions after. Then you know the rifle's zeroed. The fine point of aim we both spoke of to make sure you come back to the same spot each time so there's no scattered group. A downward point or diamond does that for me. My eyes aren't what they used to be and even with a scope(I only have a couple now)I like a defined POA.