Most of the roughness is on the top edge of the transfer bar, where it contacts the firing pin block plunger in the slide. For some reason they don't finish that surface very well.
It will definitely smooth-up on its own with use, and you can help it along with some minor hand polishing. I'll take a few close-up photos to show where.
Edit - this describes the process. I did not use a Dremel, did all by hand;
https://www.waltherforums.com/thread...-images.35563/
This gets the trigger to the point of very acceptable, and it only gets better with use.