Does anyone know how the HC-12 radio card stores its comms parameters (baud rate, mode, channel, power et c), and moreover, how many times these can be updated before that storage "wears out"? I assume it's some kind of EEPROM or flash, and has a limited lifetime.
I'm thinking about having one card addressing multiple clients on different channels, so that a client listening for commands wouldn't be interrupted by another client's conversations, but that would entail reconfiguring the device every time it needed to talk to a different client. For this application, it doesn't actually need to save its configuration, so no longer being able to save parameters in non-volatile storage wouldn't be a problem, as long as that didn't stop it changing the operating parameters. But if it's going to die after a relatively small number of changes, that might not be practical.
(I normally wire these things up with a 10k pull-down resistor between SET & GND, so the device always comes up at 9600/8/n/1, giving the opportunity to update parameters, then raise the SET line in setup(),)