Is your suggestion for improvement related to a problem? Please describe.
The built-in list has several issues (see e.g. JabRef/abbrv.jabref.org#150).

Not to mention that different authorities have different opinions about the "correct" abbreviation for a given journal.

Describe the solution you'd like
While fixing those should ultimately be done, it would be useful to be able to disable it and rely only on lists I've downloaded from https://github.com/JabRef/abbrv.jabref.org/tree/main/journals instead.