Have you tried it? worst case scenario it doesn't feed. If it doesn't feed you have 2 choices. Pitch it OR buy a wolff spring and salvage it. I have a P6 (225) and I have pro-mags that I have never had an issue with. I then bought 2 for a 226 and they are complete crap. Gonna buy the replacement springs. If you buy from scratch get factory, if you already have the pro-mag, is cheaper to just get a new spring. Good luck.
I have 4 P6 promags. They all run flawless for me. They are the only promags I own, but they seem to be fairly well built compared to some of them Ive seen for other guns.
Test it out and see how it functions. If it leaves you with anything less than complete confidence then by all means don't use it as your primary self defense mag. Keep it for range use and back up only. You must have complete confidence in what you use to potentially save your life
Since you have two factory mags just keep it and use it for the range. Nothing wrong with a free mag. Even if it doesn't work 100% it will give you a chance to deal with malfunctions.
I hate pro mags... I had two for a Kahr K9, and they refused to chamber and load correctly.. also I had one for a Sig P228.. on one occasion I dropped the mag and when it hit the ground the follower popped out..in my opinion get rid of it!
You should do what you would do with any new piece that you would introduce into the self defense puzzle. Test it thoroughly as a system. I would do that if I were introducing a different ammo, magazine, gun, holster, etc into the equation.