Maria at the lab in Melaque rushed my PCR samples to the 9:30 bus going to PV. She heard that I was stopping in the US enroute to Canada, and was going to get the antigen test at the airport so I could fly.
My results came to my email at 11 the next morning on my way to the airport...less than 26 hours after the test.

I went in on the 8:30 bus and back on the 9:40 and got the test without delay. Hats off to Maria!