I’m the Tomas mentioned in the post. I’ve been involved with FreeDV off and on for a few years, and lately I’ve been experimenting with hooking its FSK modem up to a TUN/TAP device. The goal is something like a Raspberry Pi and an RTL-SDR combined together with some appropriate software, making an IP-over-radio thing for emergency or long-range communications. Think an even more long-range version of 802.11ah. This post is David Rowe VK5DGR verifying some performance figures for the modem side of things. 2FSK is not the only option, but it is a lowest common denominator, for hardware diversity purposes.