I’m leaning this way, too. I made some templates from 3x5 cards this morning, and am concluding that more than 4 would get in the way. I’m left-handed, and have reversed the safety on my 1301T. Unfortunately, anything that comes back more than 4.5” from the front of the receiver would interfere with my index finger’s access to the safety. To bad, as I was also eyeing the Aridus quick-detach carrier - but the latch on the aft end would make safety access awkward, not to mention the aft 2-3 shells sticking down.
So I think I’ll try some -rd cards from Esstac. I also like the idea of less bulk when the cards are not attached.