I think that we should consider adding support for end-to-end acknowledgements for group chat messages (with some retires). I have noticed on my small setup of just 2 nodes, failing to receive a message is a not infrequent occurrence (have not dug into why, but it is common). When this happens there is nothing in the app which indicates if the message was received or not. In actually use, if one of these messages is something like “Are you OK?” or “Do you need help?”, if would be good to know if the message was successfully receive by the other end.
I think this has been mentioned before, but the “vine” routing protocol might be a good approach here, and the “echo” protocol for GPS info.
I know these were published by GoTenna (in conjunction with University of Delaware), but these papers were published on IEEEXplore with no caveats or disclaimers, so I believe they are safe to use… especially in an open-source project such as this.