We are having a lot of issues with importing contacts from other CRM databases, where the tables are linked together by recordIDs or other fields. For example, if we want to bring someone from Zoho into HL, their Zoho export will be a lot of tables connected by fields that are not number, name, or email.
Being able to select a unique field to import on that is different from these three would help limit a lot of issues when importing from tables that do not include these fields or reference them in other ways