What leads you to believe that the Taurus extractor is made through a MIM steel process?
I've had my PT1911 since 2008 and to date I have over 20K round through the gun with out having an extractor problem.
Best way I know to identify MIM parts is that there is usually a circle indentation left on the surface where the injection process was administered, if you check your extractor you will not find this mark, as you will on the sear and disconnector, MIM technology has improve since its inception, and like its been pointed out if your MIM part is going to fail it will do it in its early stages of wear, I honed my sear about the 10K round count, and disproved the theory made by some that say that after removing the hardened tip by honing the sear the finish will not last, because the metal is softer toward the inside, well I can tell you that this has not been the case in my experience, because my sear has held its finish for over 10K and I have no noticeable creep.
I've made it a ritual to break down my PT1911 and inspect the steel on steel wear points with a magnifying loop at around every three thousand round, and I can vouch that the steel parts used on the PT1911 are made with steel that will last just as long as those that aren't made by MIM, I still have all my original fire control parts and I'm not looking to change them out any time soon because premature wearing.
I lost the safety block spring on my PT1911 at about 12K and I re-assembled it with out the block and ran it that way for about 5K rounds without any ill affects to the slide, the trigger did get lighter and the lever never jammed into the slide hole.
I know that some aftermarket 80 series extractors, will not hold the safety block on the PT1911, but they all will fit and function and extract in the PT1911 with out the block, If you want to change your Taurus extractor with an aftermarket extractor I understand that the ED Brown 80 series extractors will work on the PT1911 and will hold the block in.
shoot safe, shoot straight and have fun