Authority Browse "See" only works for "variant" headings

EG 3.7

After much head scratching and digging, I found that Evergreen is only suggesting the "See" feature for authority fields that are designated as "variant". Turns out this is hard coded in the SQL function "metabib.browse". excerpt:

AND ahf.heading_purpose IN (' || $$'variant'$$ || ')

An example:

select acsaf.tag,acsaf.name,ahf.heading_purpose,ahf.label from
authority.control_set_authority_field acsaf
join authority.heading_field ahf on (ahf.id=acsaf.heading_field)
where
acsaf.tag in('450','550')

We see the definitions claim that the 450 is "variant" and the 550 is "related". Drawing from my limited understanding of authority control, this is correct. The problem is that some libraries may want to display the "related" search terms within the browse results. It seems that Evergreen falls short of allowing this. Making this happen requires a change to the SQL function.

I'm not sure what the solution would be. What about a library setting? Or maybe a global setting? One that contains some JSON array to list out the different "heading_purpose" that any given system may want Evergreen to suggest?