User Profile W/ Multiple Linked Emails

Referring to this KB article, please make it possible to link multiple emails to a single user. Having a large customer base, you often run into scenarios where clients will change their email domains for branding purposes or company mergers. This could lead to extensive amount of new users being auto-generated in the system and a huge pain of manual merging. We want/need the auto-generated users, we just need smarter rules to handle duplicate addresses.