P: Better handling of exporting and reimporting keyword synonyms
Currently, keyword synonyms get exported as top-level keywords; if the exported image is reimported into the catalog, those synonyms end up getting added to the catalog as top-level keywords.
Suggestion: If the export option Write Keywords As Lightroom Hierarchy is selected, then export the synonyms hierarchically, so that if they are reimported into the catalog, they get imported as synonyms under their existing parent keyword.
For example, suppose there is the keyword Family > John with synonym Jack. These would get exported into the metadata field XMP:HierarchicalSubject as:
Family|John
Family|John|Jack
When reimported, LR would recognize that Family|John|Jack is a synonym of Family|John in the catalog and not create a new keyword.
