Got it, so rather than learning to fish your self, you want to get all pedantic and imply I should move along.

Ok, lets break it down then.

Your original post had two statements that ended with a question mark, thus meeting the definition of a "question." The first:
To which I answered "Yes" and provided a supporting source here: https://www.discoverpuertorico.com/info/travel-guidelines which clearly states, and I quote:

"Travelers entering the Island are required to fill out a Travel Declaration Form through the Puerto Rico Health Department’s online portal, get a molecular COVID-19 test (nasal or throat swab) no more than 72 hours prior to visiting the Island, and show proof of a negative result or they must quarantine."

There is no "footnote" or exclusion for flights from the US. Furthermore, later in the link, the following statement is made:

"To further safeguard residents and visitors, all arriving passengers must comply with the following measures before arriving in Puerto Rico:" (emphasis added)

Again, no exclusions for US citizens/residents or flights arriving for the mainland, further they recommend testing sites on the mainland, thus again reinforcing the notion that passengers on flights from the US must meet the 72 hour prior PCR test requirement.

Now, do you agree or disagree that I have sufficiently and correctly answered the first question you asked, which was "Does that apply to flights from the USA?" The answer is unequivocally yes and I believe I've shown my work. Yes or no? If no, since you are claiming that I didn't "answer the questions that matter" I'd kindly suggest you show your work on where my answer to that question is deficient.

The second "question" you asked was:
To which the answer is no as I've not personally been to PR recently, so in this case you are correct, I did not answer that specific question. That said, do you really believe that I need to personally fly to PR and back in order to intellectually grasp what the entry/exit requirements are after reading the source I provided?

You seem to be obsessing that these are "domestic flights." That is largely irrelevant to the discussion. How is this any different than Hawaii? Hawaii is a domestic flight yet clearly has testing entry criteria. The US Virgin Islands are a US territory (thus a domestic flight) and they have similar requirements to PR. Guam is a US territory (thus a "domestic flight") but requires full quarantine for all arriving travelers.

Assuming that you actually fully read the source I provided here https://www.discoverpuertorico.com/i...vel-guidelines what, specifically, do you believe is unanswered/unclear, pertaining to your two questions? I think the supporting source document is pretty clear on how its being "conducted/enforced" if you disagree, what specifically is unclear?

My apologies if you believe my attempt to accurately and correctly answer your question of "Does this apply to flights from the USA?" (which I correctly answered) is "wasting your time" but so far your question has not generated a flood of other responses.

Regards