Not in your situation at this point, but as a photo nerd I will eventually be so I took to Google.
> Any method that I've found to clean them up (exporting the originals, deleting them from the library, and then re-importing the JPEGs only seems easiest) will lose all of the years of metadata that I've built up in the library.
Apparently when you File/Export Unmodified Originals it will export the RAW+HEIC and a separate sidecar file containing the metadata. You can then move the RAW file away and import the HEIC file, which will autoimport the sidecar metadata file too.
You lose edits though, although it seems you can "copy edits" somehow. Surely a technically inclined person can AppleScript their way through this...
Yet it seems needlessly cumbersome and should be a built-in function in Photos.app, it's clearly not prioritized because it helps funnel people into higher iCloud tiers.
> Any method that I've found to clean them up (exporting the originals, deleting them from the library, and then re-importing the JPEGs only seems easiest) will lose all of the years of metadata that I've built up in the library.
Apparently when you File/Export Unmodified Originals it will export the RAW+HEIC and a separate sidecar file containing the metadata. You can then move the RAW file away and import the HEIC file, which will autoimport the sidecar metadata file too.
You lose edits though, although it seems you can "copy edits" somehow. Surely a technically inclined person can AppleScript their way through this...
Yet it seems needlessly cumbersome and should be a built-in function in Photos.app, it's clearly not prioritized because it helps funnel people into higher iCloud tiers.