After my last post the volume I was using succumbed to corruption and had to be reinitialized. Luckily I had copied my files to another volume.
When I ran the program again to the volume with the already collected files, the files were being updated every five seconds and at the end of said update was current.
When I ran the program in SD and pressed the CMD-SHIFT-PERIOD the files were updated immediately.
I had accumulated over 200,000 files in the folder to which I was writing the files. I think that was at least part of the issue (corrupted volume maybe another factor).
I wrote a program which created a tree of folders. I appended the original app to write files to only the roots folders of the tree. I then copied the 200,000 files from the earlier program to the volume with the tree (outside of the tree). I haven’t had time to collect such a number of files yet but there is no visible delay (as of yet) with the Finder displaying the file as it is written.
Didn’t try noteFileSystemChanged:.