I really want to know how he solved this problem, which I also face:

>last year i bought a Rodecaster Duo to solve some audio woes to allow myself and my girlfriend to have microphones to our respective computers when gaming together and talking on discord in the same room without any echo

Doesn't a headset with directional boom microphone do the trick? I may be misinterpreting the problem statement though :-).

the rodecaster can connect to two computers, and we are both generally in the same discord call. so we have both microphones routed into one input for a computer, and the other person joins with their mic muted and the audio just comes from one client. since the mixing is local there's no echo. email me if you have more questions :)