This idea is to create an assignment group option that always excludes all assignments within that group from the gradebook. This would turn the entire assignment group into a collection of practice activities.

The goal is for assignments in this group to neither appear in, nor be subject to the policies of, the gradebook.  This would allow any activity to be added to the group as a practice activity without creating distracting clutter in the gradebook, and without being impacted by the late/missing policy.