Whilst flying the Mach Loop during the week would seem quite unwise, I don't see the same issues with doing so at the weekend if/when it is inactive. I get the real sense sometimes that a number of military pilots think they own the skies and are the only ones with rights to fly low.
There is an email address/phone number in one of the flight planning CAPs that can be used to inform units of a planned civilian flight through these types of areas.