I think the fine print at the bottom of the schedule contains the key to what Pdog is talking about. From that note, it seems the WAX will stop at Terminal 1 twice EXCEPT on Sundays, once on the way to Terminal 3 and once on the way back. If that is the case, there is no advantage to boarding when the bus is heading South unless we want to sit on the bus until it heads North again.
If that is true, I opt for sitting on that nice bench at Terminal 1 and reading my book rather than holding my suitcase on the bus.
However, were the bus ever to get crowded by International travelers at Terminal 3, then getting on right away at Terminal 1 would give us more options for seats. I might be tempted to do that so I could position myself comfortably with my large suitcase.
I can't quite see that very often or at all one WAX bus would be at Terminal 3, go North to Terminal 1 and do the second pickup just after a second bus had done a pickup heading South. The times just don't seem to be there. But perhaps Pdog sees something I am missing.
On Sundays we should only see the WAX going North picking up at Terminal 1.
At least that is the way I read the map and schedule.
Note also, that boarding the WAX at Terminal 1 going South (again, except on Sundays) would get us to Terminal 3 where we could transfer to the CX if there was an advantage in that route destination (like North strip access or being dropped downtown right next to the D.)
Hopefully, someone will ride this in March and give us some on the spot coverage.
Also, it is not unusual for the RTC to start a route one way, try it out, and then modify it. In fact, that has been the pattern.