A metal magazine with a plastic magazine release, that combination won’t gel with each other very well!
My fx9 has a metal magazine catch, and it uses Glock mags, and the notch in the magazine is getting chewed up.
The big difference between the two, is it’s easier (and cheaper) to ditch the Glock mags and get new mags than it is to change the magazine catch on a keltec pmr30