So maybe remove all thin LMB over 8"? BTW - Most of the pond goes unfished. Most fishing is from the dock.
IMO you have a recommendation from Bob L. to remove LMB under 12 inches so I would set that as the upper limit of the slot. The slot would then be to remove all LMB 8 to 12 and any skinny ones bigger than that. I'm not a pro, it just seems logical to me.
IMO with the very limited fishing that is done in the pond, I'm doubtful you can make a significant impact one way or the other angling.
Edit: BTW this discussion is strictly about culling right? You still plan to harvest a few bigger fish, even if they aren't skinny?