Maybe I'm being a bit like one of those BITOG paranoid people, but does anybody shake their oil jugs before dumping them into an engine? The way I see it, all the add packs and chemicals "could" sink to the bottom a lot like the pulp in your orange juice containers. And if that happened, I'd worry about a lot of it being left in the container on the very bottom. Obviously your engine isn't going to melt or suddenly implode, but if there is more you can do for it, why not? Heck your paid for the add packs. lol
And who has time to let the quart dump for 5 minutes and let it all run out? 
