“Once a proposal has been enacted, it can have no further direct effect on the gamestate.” -> Only if the proposal modifies the boards directly (i.e. upon enactment) would it be considered as making changes to the boards, so introducing a rule that would result in changes through player action (i.e. movement) doesn’t count.

(Note that this is the result of the current ruleset constraints, not what I was trying to do when I initially wanted the Hearts and Spades sub rules. My idea was to force rules that introduced board-modifying actions to be either Hearts or Spades sub rules, and thus create two separate sets of “laws” for the boards.)