After some deliberation, I ground down the mag floor plate on the 6906 mag. I ground it down such that the interior cavity was partially exposed - a very small area roughly the side of Lincoln's forehead on a penny. While it bothered me, I remedied this by filling it in, after removal of the plate, with Marine-Tex epoxy. Hardened like a rock.
I will blend it in by sanding it down even to the plate, and perhaps a touch of some black epoxy paint. If I had wanted a more perfect fix, tinting the epoxy would have been an option.
I am very satisfied with the result. I have small hands, and thus did not need the extent of pinky-rest the 6906 offers. I have just the right amount now for my grip, but w/o need to go to a totally flat plate. Also, for concealed carry, the modified plate prints a whole lot less, IMHO.
The fix cost me nothing but time, which I found enjoyable to do.