Technically, it should be possible to have an infinite (within time constraints) number of 0.5 routes per hub if the 0.5 routes went from two bases to each destination, like with:
A to B to C to D to A, where A and C are hubs and each flight is one way.
This routing is logically impossible to fly without teleporting, because ICN, DXB, and CPH (all hubs/alliance bases) each have a 1 freq and a 0.5 freq flight.