At the moment Koha::Patron->first_valid_email_address mandates a precedence of "email", then "emailpro", then "B_email". However, when "emailpro" was "Work email", a lot of people preferred to use it instead of "email" which was "Home email". The change of "email" to "Primary email" and "emailpro" to "Secondary email" was biased towards public and academic libraries, which left a lot of special libraries in the lurch. At the moment, I hard-code a change to first_valid_email_address to prefer emailpro, but it would be good if this was just straight-up configurable in core Koha.
This is something that I would like to do but I don't think I have the time to do it any time soon. Maybe March 2023.
*** This bug has been marked as a duplicate of bug 29046 ***