Interesting. So I put my right hand goes on the pillion grab handle, because I have the OEM panniers in place. I think that means that my hand is farther back than the optimal leverage (as described by you guys) would require.
I like that way of thinking about it and will give that a try.
Try grabbing the frame rail in front of the pannier or even the upper part of passenger footpeg hanger. It can help getting a lower grip as you lift.