I think it would be very helpful to add game savestates that you can use with replays or the practice duel in the deck manager. For labbing combos and different lines it would save years of my life to be able to restart when im already at a certain point in my turn.
Currently there isn’t a way to set flags as to which effects were activated in a duel or not. This would require arduous amounts of effort on both the team and the player to go through and configure whether or not each and every possible card has been activated, negated, summoned, etc, etc.
You can already configure your starting hand and number of cards drawn so that you can create scenarios you wish. You can do this by disabling shuffling in the hosting extra rules, and then placing the cards you wish to have at the top of your deck in the upper left most slots of the deck. Save the deck and then play your game to have those cards drawn.