So thanks to Kevin for alerting me to OSXphotos, which I will take a look at (eventually) and also for Nik’s reply, which makes sense, but if I read it correctly would possibly work in Nitro, but not CHANGE the titles that would still be needed in Apple Photos.
So if anyone else is interested, my research put me on to Photo Workbench (https://www.houdah.com). For about $30 (US) it does exactly what I need.
The process (for me) is to go one folder at a time (I organize by year), select all photos in the folder, click on the “Change Titles” menu at top of page, Method is Name Format, select File Name from elipse symbol and click “OK”….DONE and FAST!
I need to do some work anyway in my AP library and will use Nitro’s Flagging (mostly reject) to thin things out, but having the folders actually sorted by the same file structure as in the Finder is a major help.
Shame on Apple for this seriously dysfunctional way of sorting, but I guess it creates opportunities for the independent developers.
gary