Before sending to a specific MAC address, pairing must be performed. Repeated pairing will result in an error message. I haven't found a function yet to check whether pairing has already occurred. For this reason, I first delete a possible previous pairing and then create it again. Don't find the solution optimal and look for a better one. Does anyone already have a good implementation?

We could provide a function to detect whether a peer already exists. I would have just made a

peers

set that contains the addresses of the peers. Wouldn't that work?

I think yes. In the meantime, I've implemented a "device address book" with label and mac. If it does contain the required label then the device is already known and peered.