In agreement with your suggestion (edit:this post was moved from the Photo Mechanic feature requests into the Photo Mechanic Plus feature requests, it was posted in reply for a desire for a metadata undo feature in Photo Mechanic). In fact, I have myself other use cases that may justify to enhance the way PM handle metadata "versioning". Metadata recording as embedded XMP into the file itself is a standard, and have a bit of sense for portability. This said, there is situation where this approach have major drawbacks, this is why I will work on a well documented feature request later this year. Co-existence of Metadata recorded as embedded field AND also into the PM database + some mechanism to push records from the file to DB OR from DB to the file can get a lot of benefits: not only allowing to perform an "undo" like suggested here, but also making backups of Metadata way more efficient: when you updated metadata on thousand files, the volume required for backup all files is huge and take time (up to half day or so...). in a professional databases environment, this could lead in massive storage issue if the updates are done frequently on many photography. Instead, having a duplicated Metadata record stored into the PM database with ability to compare version with the embedded metadata + a sync functionality (with the choice of direction) can allow a very fast backup of all file's metadata in a very short time and using a few storage. In a DRP situation 1), you can therefore restore the entire up-to-date asset database using pictures files from a previous backup (done before the last metadata update) + the restore of the PM database (last version of it done after the last metadata update) and a sync operation from DB -> to file. This operation takes much less time and less backup volume! 1) disaster recovery plan.
