Let presence be the trigger
We already discussed the possibilities of using Bluetooth for communications. An additional scope would be to simple sense the presence of predefined devices and then react with a special Action.
With this you would be able - for example - to establish a special maintenance mode, if and when a special device could be “seen” by OTDT.
After switching to maintenance mode, special data and/or functions could be made available, which then disappear again, when the device left the area.