So, a time ago I implemented ADFS to my Sharepoint 2016 env. I migrated all the users to ADFS claims successfully with the help och this script: https://gallery.technet.microsoft.com/office/SharePoint-Migrate-users-ea83de43
The users looks like this: i:05.t|ADFS40email@example.com
So, is there any way to migrate them back - to Windows Claims and keep their existing file/site permissions? I want to do a roll-back so to speak.