I did virtually all my frog hunting in "Wading" water, didn't have a boat. I either gigged them or caught them by hand. Kept the light in my left hand & had my right hand beside it. Just move the hand & the light in together & pick them up, no problem.
Seems to me at the normal range you would be shooting a frog the height of the scope above the bore would cause you to under shoot a bit, did you have to compensate for this by holding over.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra