So, to arrive at PJIA need test to occur with 120 hours of SXM leg takeoff time. I think I read, French side wanting 72 hours. true?

Regardless, we are staying Dutch side but want to travel freely back and forth to beaches/restaurants.

Is there anything stopping that? Do we need fresh test results during the trip? Or is it the honor system once you enter at PJIA?

There were no checks crossing the border in late December. We stayed on the French side, so we did have to give our results to our AirBnB host. That’s it, though.

you'll be fine going back and forth. Only need the 72 if staying on French side.

no checkpoints.

Nope.