I'm guessing I'm not the only one here who has a bunch of players I try to have a game with at all times, choosing random deck & not caring about game mode. This game mode would make it more interesting in the long run.
Implementation could be a bit tricky, so I'll just throw out my general ideas & let's see what can work & not. In the examples given I send a challenge to player, always random deck / same deck / choose 3 decks etc:
We choose one game mode, first to X wins.
Random game mode each time, the first one to win 1+ more games in each game mode win the tournament.
Each player chooses one game mode (i.e. hidden+short & visible+long), randomized which game mode every game (theoretically my choice could be 100% of the games), first to X wins.
A game mode is chosen at random, first to X wins.
Whichever form it may take, the main focus is to give more meaning to the games with those we play on a day-to-day basis, as well as ensuring you always have a game going without having to challenge etc all the time.
Edit: Also, the gold coins (never used 'em) could be used to create a prize for a tournament.