The mag release is one of the few downsides I have found to the R9 -- not only the position, but mine is very stiff to operate.
I have found that putting my thumb over the top of the slide and pulling up on the mag bottom with the fingers of that hand relieves the tension enough that the catch will slide more easily. That position keeps fingers out of the 'bang switch' area too :) The empty drops into palm of left hand & if you have placed the fresh one b/t fingers of left hand, you can line it up and send it home.... its not real fast and after shooting 1911-patterned guns for 'bout a million years, I'm still having to concentrate and work on it!!
Also, as someone esle here suggested when I previously asked a similar question, you might also try putting a small piece of skateboard tape on the front of the catch.