I think the CBP check is very random, once I was at SFO and they asked me if I have any food with me, so I showed him all the dry food. We particularly packed them hand carry so that we can show it to them. He is a Chinese and I brought cup noodles and I was told to go through Agriculture lane. They randomly took half of my food away.

I needed them because we will head straight to a hotel in SFO area with shuttle and we didn't pick up our rental until the next day. So it was kind of nice not have to go anywhere.

I also heard stories about some people got their mooncake through and some don't.