I think Im very interested in more details of your experience.
On every gun I've tried to use a mag extension, or a mag spring replacement to jam in an extra round, there have been failures to feed. I'm done trying.
Often times range ammo works correctly, but full power hollow points will fail to feed. This usually occurs on the last round or near the end of a mag. One or two mags running correctly does not mean it's well tested.
Most people running mag mods have not adequately tested their gun with enough variety (
especially carry ammo) of ammo to insure correct operation.
I don't buy Smith and Wesson, Ruger, Springfield, or GLOCK so I can second guess their engineers.
I feel the same way about trigger mods.
Carry gun: no aftermarket parts (except sights).
Range gun: have at it, but be safe.