So apparently this seemingly simple task is getting harder and harder
So Hazel appears to work although I need to work out two things:
How does it deal with duplicate files?
How does it work in the background?
(and what happens / how reliable is it when I shut the lid of my laptop while it's doing it's thing (given it's automated and all)) Does it pick up where it left off without issue?).
Silent Sifter seems to work pretty well, although it did my head in trying to work out how to get the folder naming working how I wanted. (It seems needlessly complicated to setup). Once it was configured though it seems OK....
With a but.
Running a test folder of 5 photo's works just fine, seems to see duplicates and logs that, copies new ones nicely... But when I pointed it at my photo library it wanted to scan everything (read a couple of hundred thousand photos) and it was estimating over 24 hours to do that (over WiFi at the moment but I could hook it up to ethernet for the first scan if needed).
I would live in hope that it only does that once, although given this needs to run across two computers I wonder how long it would take every time I run the sift ... because any amount of time is probably going to be too long when it comes to a library of that size over WiFi.
Plan C: Fiddle with DIM to get it working better.
Plan D: Learn Apple Script and built my own script