Thanks for the heads up on the Log program. I was, in fact, having some difficulty integrating it into something other than its own sample scene.
Focusing back on MacOS, i did want to report one other finding. As i had posted originally, the Player.log or Editor.log had a lot of warnings of the form: "Fallback handler could not load library ....", and i was focused on the directory structure. The messages were all about either CsoundLib64.dylib, CsoundLib64.so , CsoundLib64.bundle or CsoundLib64.
I did go back and painstakingly re link the directories by hand so at least some of the files it was looking for i.e. CsoundLib64 DOES exist in those directories and the error message still shows up. Is there perhaps some other compatibility problem that might cause Unity not to load them?
Finally, i also noticed that the logs are looking for a file called CsoundLib64.bundle but the build has something called CsoundUnity.bundle. I don't understand the bundle process so i need to learn more to be useful on the bundles
I will look again tomorrow, don't know if any of this is helpful
I am considering trying replacing the libs in the CsoundUnity build with the System-wide ones that are in /Library/Frameworks/ don't know if that makes sense; Clearly the program works with those