I didn't specify regular season. I said international rules, which practically by definition means tournaments, although Cuba was using them in their professional league when I watched some games there in 2015, which was the first time I'd ever seen anything like that.
They do allow ties still—the most recent one was in 2016, which is why the Cubs finished 103-58-1—but my impression is that ties can be declared only when games would be suspended by darkness or equipment failure, or in the 2016 case, by weather with a subsequent league decision not to make up the game. I don't believe it can be a discretionary decision between teams to save their pitching. If weather or darkness is not an issue, they play the extra innings regardless of whether they want to or not. Is that not correct?