This is part of DAM which it’s arguable will take Photo Lab in the wrong direction. Performance improvements with existing features and keeping up with new lenses and bodies from supported manufacturers (not suggesting adding new manufacturers) are the core of improving the Photo Lab experience and to maintain its competitive lead among RAW converters. If I could vote against EXIF editing I would.
There are much more powerful EXIF manipulation tools out there. One of the most capable (and affordable) with batch functionality is Better Finder Renamer and Better Finder Attributes. Exiftool is free and incredibly powerful but command line. If you’re just looking for a quick path to the EXIF of individual files in an easy to use GUI, Lyn is brilliant and also cheap as chips.
Graphic Converter can do some of this but I find Graphic Converter expensive and overkill and don’t like the interface. Last version I own is probably v6 and it’s currently on v10. I took a quick look recently - while somewhat updated visually, Graphic Converter is still not a pretty tool.
DAM and Lyn limitations: Lyn is not particularly useful as a rating tool as it’s ratings don’t move back and forth between different applications consistently. Lyn is useful for quick preview of folders, slideshows, EXIF one off editing and culling rejects. FastRawViewer is a much better rating tool as it uses sidecars which Photo Lab, Capture One, Adobe Bridge, Lightroom and others read. Canon DPP doesn’t seem to read the FastRawViewer ratings but FRV reads DPP ratings.