You may look at mine mods:
https://forum.invisionize.pl/files/file/889-dp42-exif-forum-attachments/
https://forum.invisionize.pl/files/file/890-dp45-exif-gallery-images/
You may check my mod for the licence keys, works in another way but maybe you would be interested.
https://forum.invisionize.pl/files/file/774-dp45-single-use-license-keys/
You may try reach him on his official board - https://www.devfuse.com/forums/
Many people have been attempting it for several months, but have yet to achieve any success.
Do you have set table prefixes in the conf_global.php file? If yes then it would be easy - export only these tables as a SQL dump, import them into a new database, and update access details to that db in conf_global.php file.
It's "standard" fields from that table (based on core schema.json) and if the DB checker didn't find anything wrong then he must have this field in that table.