I'd rather Osuna not pitch the rest of the series. That would imply the Jays won't need a closer the last three games.
Not sure I would classify that as a "bad" start given he pitched into the 9th and Giles allowed all three runners on base to score after he left the game.
He should never have pitched the 9th to begin with.... but once he put all 3 runners on base without recording an out, it did turn into a "not great" start.
I prefer ballplayers that hustle running to first no matter what. That way...if a mistake happens, then you get on base. By not hustling all the time (up to when you see the ref out signal), you just give it up no matter what.