nabla: For Compromise Chess, I had never heard of your "forced move ends the game" rule option, until you mentioned it.  I would still prefer the "forced moves must be played without compromise" option, for two reasons: (1) it was what the game's inventor specified, and (2) my admitted personal bias in favor of endgames, and the way endgame theory changes in specific variants.  I'm afraid that in the "forced move ends the game" version of Compromise, very few endgames would ever be reached--we would virtually lose an entire phase of the game, for no good reason that I am able to see.