would dumb down the game imo.

part of what separates the truly great players from the average ones here in SE are 2 things:

the ability to make a well-tuned deck
the ability to sac properly even with a bad starting hand

one of the reasons why i still play SE even with HS around is that i feel HS is too dumbed down. i feel no excitement or rush when playing it. there's no mental pressure. a lot of the moves in HS can be done half asleep. you don't even have to agonize over sac choices.

one of the mechanics i love in SE is saccing. everything about this game is making the correct sac choices. adding mulligan gives players with weak saccing abilities a free pass.

reason why i love SE is that you are forced to deal with a bad starting hand. not only that, but you are forced to sac with already a bad starting hand. these things allow for the better players to rise and for the weaker players to fall.