Hi ManoMusic, to create a custom column in Mp3tag list view is easy work in Mp3tag.
A short description about the dialog "Columns" do you find in the Mp3tag manual pages in the section "Columns".
Mp3tag allows the user to store any key-value pair into a supported media file and to read back.
Once the media-file has been tagged by the MusicBrainz service, the file may hold a bunch of MusicBrainz related tag-fields.
MusicBrainz tag-fields and their content may look like ...
MusicBrainz Album Artist Id:'89ad4ac3-39f7-470e-963a-56509c546377'
MusicBrainz Album Id:'40bac1a9-f093-4771-8eac-96497d85b76d'
MusicBrainz Album Release Country:'XW'
MusicBrainz Album Status:'official'
MusicBrainz Album Type:'compilation'
MusicBrainz Artist Id:'329a506c-6e32-4b8c-bbb2-334054d4a4c2'
It is just a matter of configuring the Mp3tag dialog "Columns" to display the content of such tag-fields along with the other tag-fields in the list view, and it is also a matter of how important or informative it might be to display those data in the Mp3tag list view.
At end it is your decision what you want to display and what is neglible.
I have attached a picture showing the dialog "Columns", in german language "Spalten", regarding the tag-field "MusicBrainz Artist Id". I assume it is self explaining.