My use case: I am using MC to graphically organize a bunch of Linux isos and container images that I spin up during software testing on various platforms. I would like to organize these files on my disk using MC but they are sometimes held open by my container manager or torrent software that I used to acquire them. I would like MC to create and point at a new hard link so that those programs can still have access to the original inode reference. This also comes in handy when ripping or remuxing videos using software that holds output files open for long periods of time (some of my HQ rips take several hours to complete, meanwhile I want to be able to organize the output files in MC simultaneously).
I would also recommend disabling tag updates to the new hard link by default, that way the function of the previous program holding the file open will be unaffected by any potential file updates made by MC on the inode via the new hard link. Perhaps a new library field could be used to track the "write protect" status on individual files. I suppose that this is another major feature that would need to be introduced to get this system working reliably but one that would be beneficial for a number of other reasons (creating a "cold storage" subset of a library with tag updates enabled by default).
What would really be amazing is if MC could automatically turn off the "write protect" library field when the original file was deleted (so that only the hard link that MC made remains). It should be possible to track the existence of the original filename reference during auto-import and disable the write protect field on the hard link once the original filename has been removed. This would re-enable tag updates once MC was the only program referencing the inode.