Sorry to answer so late in the game. You probably could have at the hour mark, but ideally it's best to wait till your next make to use your new mold. You might have ended up with mechanical openings in your cheese, which aren't the end of the world, and you might still end up with some if the pressing weight isn't heavy enough. Research pressing weight. If you need to make the switch, a good idea would be to reserve the whey to heat the curds back up to help them knit together better.
