All hail arbitrary Apple, unbound by contract or law! Save us from ourselves, Tim Cook!
"Apple grants you...license to....
(f) Allow Your Customers to use Your Internal Use Applications on Deployment Devices, but only (i) on Your physical premises and/or on Your Permitted Entity’s physical premises, or (ii) in other locations, provided all such use is under the direct supervision and physical control of Your Employees or Permitted Users (e.g., a sales presentation to a Customer);"
FWIW, I am a paid-up, registered member of the Apple Developer program, but still can't access that page, as it is apparently limited only to enterprise developers. So I can't check the definitions/details myself.
That limitation also helps me understand why so few, here or in the journalistic coverage I've seen, seem willing to quote the exact section violated. Those curious and willing to answer perhaps cannot access the formal wording, whereas those with the rights to access the terms may fear they'd be violating some obscure provision of their Apple agreements by merely quoting it.