To demonstrate this point, here's the EV of flatting these hands vs BTN, CO, and HJ and no cc:
As you can see, our EV is actually worse against a loose range as opposed to a tight range.
Please note that this is a 200z rake sim, so at 5 cent, this EV of flatting in sb is godawful in general. I haven't seen a 5c sim, but I would imagine it might remove a flat frequency entirely.