Hi @dduffy,
Would you be open to sharing this idea on our feature request forum here: https://mattermost.uservoice.com/forums/306457-general?
Also, if you see usernames that don’t fit to naming conventions, you can update user information via, e.g. API: https://api.mattermost.com/#tag/users%2Fpaths%2F~1users~1{user_id}%2Fput?