No. Do your laundry as you would do it without the washing bag. For example, a dark-colored shirt inside the bag with whites outside the bag doesn’t make sense. The washing bag doesn’t change that.
If so many fibers do not break in the first place, you will find less of the already tiny microfibers in the corners of the Gupyyfriend washing bag. However, the lifetime of the clothings are extended. Our preferred plastic fibers are those that do not shed at all. Further tests are taking place and a scientific publication on this test series is in the planning stage.