I had to look around to find a datasheet[1] for the BK4819 which is the heart of this rig, but it appears that there are I/Q outputs on receive, and possibly I/Q inputs on transmit internally, so it's an SDR, and not limited to FM only. The low output power will likely restrict it to line of site, but it's an interesting substrate on which to work.
[1] https://touchardinforeseau.servehttp.com/f4kmn/f4kmn/FRANCAI...