The *only* time a BAF| strike force is allowed behind enemy lines into Kusari is under direct approval from an Admiral (In this case Rubber.Duck) it is his call to do so, in fact any of the Admirals have the right to lead a mission there if they A. Deem it fun enough and B. Think it practical.
I wouldn't send them to New Tokyo, or to Honshu, that's what the QCP is for. But Kyushu once every now and again, don't see the harm in it.