Mathias,
I think you have misunderstood. Mp3tag is not configured for roon tagging out of the box. You have to configure mp3tag yourself. The “roon relevant” tags you see in my screenshot I have added to the editing pane of mp3ag myself to make my life easier.
There are no easy alternatives that I am aware of other than working your way through the mp3tag manual. There might be some youtube videos to make the learning curve a little easier.