I have absolutely zero concerns with game duration. I think MLB's efforts are misplaced with that regards. Nobody is going to be less of a fan because of an extra 10 minutes.
Winning or losing one game out of 162 is so inconsequential--I think nearly every team would rather have this rule in place than possibly get stuck playing a 16 inning game that depletes every bullpen arm, then brings in a starter to really fuck up the rotation and hurt their team for multiple future games.
The runner on second removes those games, which unfairly hurt teams in the grand scheme of things. That's why I am strongly in favor of this rule.
I'd also be fine with it just being a single extra inning, and if we're tied after 10, call it a tie.
As long as you don't apply these rules to the postseason, I'm all in.