Ordered a stock replacement ambi mag release. (Should have ordered a left side only... more later)
Cleaver design FN has for holding the ambi-mag release in place. Once mastered it's pretty easy to do. Cleaned up the left side release button, degreased it, ran wire brush over it. Then wrapped it with a strip of Gaff tape forming a pocket. Took about a pea sized, may butter bean, piece of Bondo and tamped it in the "mold". Tamp, tamp, tamp. Let it cure. Removed the taped the sanded/filed the Bondo till I have an 1/8" extension. Brings it out enough so it's above the level of the grip. Makes changing mags so much easier.
Uh-oh. No the gun is too wide to comply with IDPA CCP specs. Wait, it's too wide because the ambi-mag release is too wide. Huh. Ground down the right side button, dunked it in cold bluing then buffed it a little. See I should have ordered a non-ambi release. What a difference 1/8" makes. Don't know when I'll run it in IDPA, but I'm ready now.