You could likely open the inlet to install an aics bottom metal and make the mdt polymer double stack 3rd mag fit flush. However you'll be limited to 2.85" internal.
I'm a big fan of the 3 round flush fit AICS mags in a flush fit AICS bottom metal that has release button inside the trigger guard. As mentioned, the limited OAL for SA rounds is the only issue for me. The lack of edge/under/over hang of the MDT flush fit is very, very nice for a hunter.
A thin metal AICS 3 round flush fit AICS that allowed longer OAL would be real improvement. The issue of magazine deformation would be limited while installed since it's a flush fit, it's protected. Perhaps a thicker inner corner and bottom seam with follower machined for clearance could be the helpful in avoiding deformation when carried loose in pack/etc. For higher round mags there are options, but not for a flush fit AICS...it would be an improvement not offered by anyone else in a standardized and highly used mag across multiple platforms.