Judging by what happened on Halloween. I won't take any chances, and will open my gifts later on, just in case. "We weren't expecting the lag to affect the presents."
Jokes, but either way. I'd rather wait for the playercount to drop, since I don't see how opening gifts during this lag is enjoyable or even necessary.
ALSO, if you received a gift from me, you better read what I wrote, because I gave a different message to everyone.