If you are militant about open source, then meshtastic is the only way to go because the meshcore client applications are closed source and so is some of the firmware for different devices. I didn't touch it for over a year for that exact reason until an app called meshcore-open that fixes the bug of the other app being proprietary. I still have to watch out what firmware I use though, because as I said, some of it is still proprietary. Like, I think the TDeck firmware is proprietary.