We require users to access Smartsheet via Single Sign On and experience many domain changes due to rebranding, which often results in multiple Smartsheet accounts being created. Because we don't have a centralized instance of Smartsheet, we had a workaround to merge user accounts. It involved using the alternate email feature in user profiles and adding a 3rd email to "free up" the new email.
Smartsheet made a recent change to restrict an individual user from changing their primary email address so we can no longer do this. The solution provided by Smartsheet is for us to temporarily "activate" our domains, use the user merge feature and then turn off the domain activation. We have 14 instance of Smartsheet with shared domains. Activating domains will prevent other instances that share our domain from adding users so I don't want to do this. Also, temporarily turning a feature on and off to solve a recurring problem does not feel like a robust solution.
I'm recommending System Admins be given the ability to change primary email addresses, regardless of whether the email domain (e.g.: @smartsheet.com) changes.