I don’t have direct experience, but I’ve volunteered at events with Mexico teams in the past for what its worth. I’m not certain but I think they have the same issues other international teams have with shipping batteries (they can’t). This is easily solved with local teams lending batteries.
Last year we had one (rookie?) team whose robot got held up in customs. It was the only time I remember this happening in the past 10 years. Other teams came together to help them build a kit bot so they could still compete. I wish I had more advice here, but since I wasn’t directly involved I don’t know what the issue was. Just stay on top of shipping status.
Finally, we also had the experience of one of our Mexico students lost his backpack, which also had their passport. It turns out that the pit next to them accidentally packed it up with their stuff and we were able to go to their school to find it, but it was a big scare nonetheless. What we learned from that was to have the phone number on hand for the consulate for any international teams , and possibly contact them ahead of the event to get a sense of who might be on hand over the weekend. (If memory serves, I think the consulate was closed saturday, so we took a shot in the dark and called a Spanish reporter who was at the event that morning, and he happened to have a friend at the consulate.)
Hope this helps and good luck to y’all!