I tried macOS Photos' default duplicate merge behavior and it made a choice on what to keep that was disappointing. But if you open the Duplicates album and select all, you can then add them all to a new album. Then you can inspect them carefully and hand enter metatada, manually assign to albums, etc.
Then you can inspect them carefully and hand enter metatada, manually assign to albums, etc.
Of course, it might be simpler to just do that while they are in the Duplicates view. Then, if you want, you can choose to delete one. There's no reason that I can think of to use a separate album.
But merging has advantages. In merging the final picture goes into all the albums that contained either one. Merging usually combines the Metadata of the two pictures, and selects the one that is higher resolution, if that's a difference. Sometimes the choice does seem weird, but you can undo it.
Then you can inspect them carefully and hand enter metatada, manually assign to albums, etc.
Of course, it might be simpler to just do that while they are in the Duplicates view. Then, if you want, you can choose to delete one. There's no reason that I can think of to use a separate album.
But merging has advantages. In merging the final picture goes into all the albums that contained either one. Merging usually combines the Metadata of the two pictures, and selects the one that is higher resolution, if that's a difference. Sometimes the choice does seem weird, but you can undo it.
Tip: Instead of merging Duplicates add them all to an album
