I built up some compliance mags for my parts count.  BS I know.  But with slow joe and the hoe , I’m legit. They lock back with one round left. 4 ea mags I built up.  These are military fal mags.  The hump appears the be in the exact location of an unaltered mag.  No big deal . Just range mags.  But curious.  The DSA spring is different from a standard mag spring. It’s squared off . A standard spring will not work as far as I can tell on a polymer follower . WarDawg

Pretty sure you just need one mag onhand to count for 922....so in other words make one mag then you're covered.