Editing metadata disables Live Photo!?

So I’ve gotten tired of apps like Photos, and many others, that store metadata in a database rather than using the industry standard photo/video metadata fields. In the past, I used Lightroom to edit metadata, but got sick and tired of Adobe’s subscription model. Lately, I’ve been using MetaImage and NeoFinder to replace LR, and they’ve been great. Then yesterday, I go to open a Live Photo in Photos in MetaImage, and it says doing that will disable the live photo!? Why? From what I can tell the live photo is stored as a HEIC file for the still and a MOV for the live part. Both support EXIF and XMP metadata. Why not just sync the metadata between the two files?