I do not. User specific columns, in my opinion, is reserved for sheets that everyone should have access to where the user’s email isn’t recorded per row. eg. a checklist, choice component, (eventually) like component, etc. I also see this working as a way to record personal notes on articles, posts, etc.
eg. An inline list of articles. At the top of the article is a notes component that’s pointing to a “Notes column”. In the past, this notes component, when filled out, would be visible to everyone because the app-user email isn’t assigned to the row that houses the article. However, if you make this column user-specific, each user can fill out the notes component without affecting other users.