I made something to compliment my front pocket CCW habit:
This is just hot-glued together proof-of-concept, but works exactly like I want. I will use it in my weak-hand rear pocket, not my front pocket, but it's a lot harder to take a picture of your own butt than your front pocket, so just pretend--you get the idea. I'm going to make another one more carefully, drill the hole so I can still disassemble the magazine, and epoxy it on.
When the magazine is in the gun, there is just barely a gap--you can't really tell from the pictures but it is almost perfectly flush with the grip...if I'm touching it at all, and my regular grip barely does, it just feels like the magazine flares out slightly. Also, it doesn't interfere with inserting it--the pistol grip is just as wide as the base plate.
I'm definitely going to make a more refined version of this, it's probably one of my favorite ideas ever to compliment my usual pocket carry. No more uncomfortable funny-angle mag poking me in the ass!