Working with 2 or more name authority files : Implement new Marc21 subfield $2 -
Marc21 Format change from May 2019 introduced a new subfied $2 in bib headings.
$2 contains the source of heading of term in name or name-title and title headings (http://www.loc.gov/m.arc/bibliographic/bdapndxg.html)
This subfield $2 already exists for use with 6xx headings, 2nd indicator 7. With this format change, Marc21 introduce the $2 in 100-700-800/110-710-810/111-711-811/130-730-830 fields.
In Alma, links with Name/Titles authority file can be made only with 1 unique file, unless you use the Authority Priorities. Unfortunately, Authority Priorities is not convenient to all situations.
Other linking possibilities based on $2 value would be more consistent for authority control.