So the takeaways here are:

- SXM (or the airlines) CAN and WILL deny you entry if your forms are incomplete or incorrect
- SXM MIGHT deny entry even if you forms are correct based on technical reasons or grounds that may be incorrect or unclear, so submit the forms as early as possible to give yourself time to re-submit if needed
- It's advisable to have multiple negative tests from different providers in case one gets rejected. Because of the testing delay and the short time window, it is advisable to line up multiple tests beforehand
- Carry paper copies of your test results and pre-authorization when you travel
- Be on the lookout for double charges for insurance if you have to re-submit

And finally:
- Carib is clearly superior to both Presidente and Heineken