I've had losses where I was already down 5/6-0 and it was only turn 1 with me yet to play - but I've already lost datatracker, and two specialists and regardless of anything I could do, I was still going to lose. There was no way to claw back a draw and even a minor loss was out of the question. I just push for retreat (where it counts) by the end of my opponent's turn 2 (if I'm going 2nd). The best I can do is to prevent him getting a final turn to grab remaining objectives. It's more "kuang shi" mode than a concession. You can't kill me if I'm already dead.