I haven't done it in a year and a few months, but the first time we went, the check in time was closer to the fireworks time, and we had to eat and move to the garden quickly. The next time (I think I've only done it twice?) the check in time was much earlier, and we figured we could use the time to enjoy at a more leisurely pace. We got in after about a 10 min line to check in, everybody sat down, we ate, and then EVERYBODY else BOLTED for the garden. I was confused, we made our way over to the garden earlier than expected, but there were more people already there than the first time we went.
I didn't see many of the items on the buffet replenished (it could be that the "extra" items weren't replenished that I noticed) throughout the night, but I might have just missed them.
But also, I would't ever think of going to pick up my wristband and then going somewhere else to do something......because that would involve getting through the people, getting in a line, doing whatever attraction it is, and then getting back......and that would make it too close time wise for my comfort. If you wanted to cut down on time there, I would just show up an hour in advance of the fireworks, and you would be able to get your snacks/treats at a nice pace and then get a spot in the garden.