Yes!!
the fix!!
The last one did work! Setting system priority does work! Baldurs gate is back to running the way it used to.
I was concerned about trying to use the fix, so I inquired ChatGPT for extra explanations and instructions:
https://chatgpt.com/share/673fa587-d158-8001-9701-84db2b533a24Setting priority to -15 worked for me just fine.
One of the issues I was concerned about was how setting system priority to the lowest value of -20 (which is the maximum priority) may affect MacOS running. By giving overwhelming priority to BG3 you may impact essential OS processes, in theory. Again I set priority to -15 and still was able to smoothly use messengers and a browser, but your mileage may vary depending on how powerful your system is.