Most of them will have port 30004 open for their ingest domain, usually feed.domain.com. Thus you'd hook up socat to 127.0.0.1:30005 (i assume you run dump1090 or readsb locally as a decoder). And make socat send that to feed.adsb.lol:30004 and/or feed.airplanes.live:30004
If you're in a remote location, you don't need to worry about mlat-client as MLAT requires at least 4 receivers that receive common aircraft.