Service Principal as authentication type for SharePoint folder

Just spent the better part of a month trying to setup a SPN for a SharePoint site connection for Power BI only to be told it's not supported! Documentation on this is also lacking - our local Microsoft support team also did not know about this. Organisations have a legitimate reason to need SPNs instead of a user account to connect to their data. - Users leave - Reports are built and managed by teams - SharePoint is sometimes the only acceptable storage option - you don't want a fake user to hold a Power BI licence - you want to schedule data refreshes - you want least privilege security without having to deal with password resets (service accounts) All of these are reasons and more why organisations don't want to use OAuth or service accounts as the authentication method. Please expedite SPN support for SharePoint Online Folders ASAP.