A declare to FSCompareFSRefs could be used on OS X, passing in the each item's MacFSRef value. Note that FSCompareFSRefs is deprecated by Apple as of 10.8, along with all of the other functions that deal with FSRefs.
The reason NOT to use AbsolutePath etc is because Mac users (unlike Windows users) expect an app to find the document even if it has been moved (for example from a RecentItems menu).
As FSRef is deprecated how does one deal with this now? Is there a replacement that can still open moved files?
Could FSRef still be used on HFS+ volumes and URLpath on APFS volumes?