I have some numeric exposed filters and the operation is "is between". Views prints out two text boxes with the label above the first one, the second with a label of "And". However, when I add it to the Secondary section, the "And" label appears, but the main label does not appear.
Looking at the view object, it seems the label for this hybrid field is in the
$form['#info'] or something like that and not directly attached to the first, minimum numeric field. So it seems Better Exposed Filters would have to add some code to bring these labels for the compound exposed filters along into the Secondary area.