You see, my standards of resignation in this spot (and in my ongoing games currently) are laxer than they'd be in a serious game, see
this post for an explanation. Currently, I'd just like to get frustrating games off my chest quickly.
E.g. here's my most recent resigned position on chess.com; note that it was vs an FM; I felt I would have been utterly lost (taking the difference in endgame skills into account) had I exchanged the queens, and there was no way to avoid the exchange because otherwise Black would have just invaded my queenside with his queen and gobbled a pawn or two. Stockfish gives me about -2 here.
In the final position of the Malkovich game, I thought I was -1.5 at best, again, vs a better (though untitled) player.
In a serious game, I resign when I feel that Stockfish would give me -3 or worse.