Hopefully the limited helmet editing can be addressed in another game patch. I can see why you are frustrated over this Michigan helmet with not being able to edit the entire area of the helmet.
I would assume this can be fixed/updated in a patch but the developers definitely need to know about this issue. Maybe Spear or Ridin will see this thread & chime in. If not, if I were you I would make a separate thread reporting this issue or add it to the Bugs/Glitches thread that is pinned in this section. Thanks.
Thank you. Added to the Bugs/Glitches thread. Done!