Sounds a little confusing. If I announce mate in one or two, I could be incorrect. Do we stop to prove it? That would spoil the cadence of the game.
Also, it would be hard to play blitz or speed games.
Penultimate chess is satire. To mock the checkmate condition of standard chess, which is similarly ridiculous, instead of playing natural chess: to capture the king.
I thought it might be satire but I never joke about chess. :-)