1) From a practical and safety standpoint, the lockable disconnect
serves no purpose as I see it. I think most wrenches would agree it's a
control issue with the utilities. So long as there are other disconnects
in the AC interconnection line, I never see it being used. As it's been
pointed out, lineworkers use safety protocols that should trump a
lockout switch and the thought of a lineworker in your neck of the
woods, driving his lorry many kilometers away from a downed line just to
lock out a 1000 W source just doesn't make sense. Furthermore, if the
utilities find a customer is in violation of their interconnection
rules, they can just pull the meter.