When using "Catalog sync" at least in scan mode "full", all photos are verified for changes. I have organized my photos in subfolders per year. So my catalog has all years in its root, but most of the times changes occur only in the "2023" subfolder at the moment. It would be a real time saver if one could point PM to just verify this specific subfolder "2023" or even deeper in the directory tree for changes.
Best regards, Markus