I have a couple of questions:
Does this extension support Google groups?
I noticed that the backup made with syncing the Google account is not accessible to the user (it's stored in a hidden folder in Google drive) Is it possible to download the backup "outside of the extension itself"? Because on Google drive the only options I have for that is to delete the folder
Thanks for posting your questions!
Yes, Tabox supports Tab Groups, in fact we were one of the first tab managers to do so!
You cannot access the sync file directly (that is a Google Drive restriction) but you can get a copy of the exact file by exporting all your collections to file (from the settings menu, scroll down to "Export all collections".
Hope that helps, please feel free to post any other questions or email them to firstname.lastname@example.org