The button can be galled (worn, forming metal ridges) by the titanium, or Ti coated T piece that actually releases the mag, you can pop the trigger release apart and reshape, which helps alot, esp. if its 'hard' on one side and not the other (then flip it, the unworn side is you dominate release)
AS for the P64, I like the original springs, sorry but... I would hate to think how light my SA would be, it's ~2 pounds now, BUT you do need adrenalin or crazy gorilla hands to fire it DA.
As for a gun smith, well MOST US gunsmiths will have NEVER touched, let alone know the 'quirks' of the 82, all they have is a better pick set than you.