We were coming home from a cruise. We were using AAdvantage miles for FIRST CLASS travel home. We arrived at the airport about 45 minutes before our flight, knowing that we could check in at the 1st Class counter and that we both hold Global Entry Status meaning we're also TSA Pre-Check. AA usually starts boarding domestic flights 30 minutes before departure, so we should have had ample time.
Unfortunately, at the check-in counter we were told that in Puerto Rico one must have checked in ONE HOUR prior to departure, AND your bags have to be cleared through an additional Dept. of Agriculture screening before being presented for check-in.
We missed our flight because of the (previously undisclosed) extra steps, though we were "accommodated" on the next flight out. We also missed our in-flight meal as the next flight was in Coach.
I'd also note that the San Juan airport is extremely crowded and has almost NO OUTLETS available in the concourse area. If you hope to charge anything, be the person who brings a power-strip and you MAY be able to share an already-occupied outlet.