Not a fan of most of those rules. No justification for them except trying to be different to possibly speed up the game. If they want to do that, set a time limit and once time is up, it's innings over. If you haven't bowled the full 20 overs - too bad. Bowling team controls the pace of the game, if the batter tries to delay the game, take runs off.
I don't mind the designated hitter / fielder rule though, teams batting first often do this now anyway.