Separate metadata merge options for pixel dupes

[roachcord3]

I would like an option to have a separate set of metadata merge options for dealing with pixel-for-pixel duplicates. This would enable use cases like:

• Copying tags on local tagging services meant to indicate files that you want to do some operation on, but only for pixel dupes. For example, I use a tag locally for files that are low quality that I intend to go find a higher quality version of later, and it would be nice to not lose track of those. Pixel dupes mean I haven't solved that low quality problem yet, so I'd want to keep that tag. In other circumstances, I'd be actually getting the better quality version, so I wouldn't want to keep the tag anymore.
• Copying URLs, but only for pixel dupes. Most of the time, these sorts of cases are basically the same file, just with different metadata/png compression/jpeg encoding (progressive vs baseline.) Either URL may be desirable to keep, since it is essentially the same image and can be found in either place, just with minor metadata/encoding differences. (Not my use case, but I can imagine someone wanting to do it.)

I think this should also apply when dealing with jpg-png pixel dupes.