An afterthought...
If the release can be switched, I wonder if it will work with factory mags?
(Seeing as how factory mags have the release notch on one side only, the reversed release may have nothing to "uncatch" when its reversed.
You may also have to cut new notches in your mags, or go to using after-market mags (almost all of which have have release notches on both sides of the mag), exclusively.