Last year residency status under substantial presence test

Hi,
After studying IRS 519 in-depth and reading many discussions on this platform,  I am still wrapping my head around the question whether I have the option to file my 2023 tax return as a resident or am I obliged to file as a dual-status individual?

Here are the details of my situation:
- a) I have been living and working in the US from 2018 to 09/2023 with my spouse and kids.
- b) We are not-US citizens and were on an 'O' visa for the last years.
- c) We returned to our home country in 09/2023 and had foreign income throughout the year.

Here is my interpretation and the issues I am hoping to get some input from the community:
-1)  I clearly fulfill the substantial presence test for 2023, not the green card test. --> I am pretty sure I am a resident for at least part of 2023
- 2) IRS 519 says: "If you were a U.S. resident in 2023 but are not a U.S. resident during any part of 2024, you cease to be a U.S. resident on your residency termination date. Your residency termination date is December 31, 2023, unless you qualify for an earlier date, as discussed later. " --> I assume this means resident status for the entire year of 2023?
- 3) "Earlier residency termination date.You may qualify for a residency termination date that is earlier than December 31. This date is:The last day in 2023 that you are physically present in the United States, if you met the substantial presence test --> I fulfill this criterion but it is not clear to me whether "may qualify" indicates an optional choice here?!
- 4) I assume residency termination date before 12/31/2023 would make me a dual-status individual (meaning I could not file jointly with my spouse, and had to submit both a 1040 and 1040NR to the IRS), while residency termination on 12/31/2023 would allow me to simply file a 1040 form married-jointly (and make my foreign income subject to federal taxes the whole year?) --> again, I am wondering if I have a choice here?  

Thanks so much for your insights!