I THINK that would be OK!
Actually, that would be great, if you can just do it as a background task.
Just like updating orders and listings (which actually takes many minutes).
Can you just do the “updating” on a background thread and let the Smart Groups populate as the progress continues with a small progress bar up near the toolbar.
I know… This is much more effort… But the current results are not consistent…
Sounds like this would be pretty “quick” for most users with <1000 listings?
And for those of us that have many hundreds or thousands (me >21500) of listings, ACCURACY is VERY important!
This way, there would be consistent results (with 1 and only 1 evaluation engine) between the Search field, Smart Groups filter editor clicking OK, and Smart Groups when changing an item.
“I THINK the macOS runtime comparison methods seem to be correct.”
Yes, the macOS runtime comparison methods would be best.