For this exact case I have built https://chiph.art/en/project/2026/dj-usb-toolkit

The parity repair in the app should make the USB compatible with all CDJs because it makes both of the DBs identical.

I have also been able to repair the DBs that have been corrupted for example by disconnecting USB while Rekordbox is exporting to it.

I'm also just now building a website where you can send the DB repair requests for cases that need special attention.