Thank you for the post. You are adding valuable threads to this forum.
Let me ask you: If you were Black after Kxg1, would you resign? I'm in NO way qualified to correct a gm in this game, but doesn't 35...Q-f5 at least cover the mate at f8 and block the passed pawn? Is there enough of a flicker of a hope for ...Q-g4 and just the vague outline of endless checks or R-h1+? Sure, 36Q-d8+ and 37Q-d7+ removes the Queens and the Black pawns start falling to the active White Rook, but at my level would there be just a bit of hope to play on a few more moves? Of course if I'm missing a 1-mover or tactic feel free to embarrass me with a correction.
I guess at my level I just hate to put up the white flag.