-As a current supervisor, located in the U.S., I can tell you that we are no longer counted on to work "on frequency." We do have a requirement to maintain currency (8 hours a month), but that is typically accomplished during low traffic times (early am, late pm). It's not enough time to be "current" but it is to remain familiar.
-Other duties include micromanaging the operation, position assignment, training administration, log-keeping, time-and-attendance duties, performance management, answering the phone (regardless of the source), and many others.
-We are referred to "Front Line Managers", but I understand a change back to "Operational Supervisors" is in the works.
-We are not part of the bargaining unit/union.
Hope this helps.......