All non-isomorphic PA^*₃(6,2,4)s, the number of runs, a lower bound for D-efficiency and D-efficiency ordering (.n means that the design ranks number n in the D-efficiency ordering):

Packing Array             Number of Runs             Lower Bound and Ordering  
PA^*₃(6,2,4).1                        44                                   (97.7037%).1
PA^*₃(6,2,4).2                        44                                   (97.1657%).2