Thanks. This is a good workaround, a much more elegant workaround than I used to use (I used to set conditions that could never be met in order not to show a field group on any page, like assigning a field group to a widget), but it’s still a workaround and it might be confusing because it makes a field group marked inactive on the list, when in fact, it’s not inactive.
So it would be great if a field group could be left unassigned.