Any competent gunsmith should be able to get your M&P trigger down to 2.5-3 pounds.

While working the chrono stage at various USPSA matches, I've shot dozens of M&P's with 1 pound triggers.

Personally, my M&P 9L has an Apex sear, RAM and competition spring kit installed by me. After a bit of polishing and fitting, I got it down to 3 pounds easily.

Jeff