However, you can easily quickly carb without over carbing by simply set it at the desired pressure (12psi for example) and then rolling the keg back and forth for 10-15 minutes or whatever works. That way, it's doing the same thing without the possibility of over carbonation. Just make sure it sits for a few hours to let everything settle inside the keg. I did this method the night before thanksgiving for my pumpkin. Set at 12, rocked it for 15-20 minutes, let it sit over night, tested in the morning and poured a perfect carbonated pint. AWESOME!
With that said, if you have time, the set and forget method is probably the best though. Lots of ways to get to the same place.