I'm guessing trigger, safety/barrel selector, and possibly barrel and forearm release levers.
MIM is not my favorite. I have a couple MIM parts on S&W. I'm not excited about it, but you can't tell by looking at it. However, gunsmithing becomes an issue
There isn't anything wrong with MIM parts, per se. One of the best S&W revos I have has some MIM parts. They haven't broken and it is still one of the most accurate 629s Smith ever built. (full cylinder of full house loads under 2" at 50 yards out of the box)
A 1911 I have has a bunch of MIM parts - again no problems. Parts machined from forgings
may be stronger than MIM parts... but that does not mean that MIM parts are inadequate. Casting used to mean junk. Now it's and industry standard for a whole bunch of stuff.
It depends on how well they are made....just like forged parts. A well made MIM is better than a shitty forged part.