Oz's (both grade 3 and expat), the only problem that I could envisage with making the lane an MBZ would be for "non com" a/c (such as some ultralights etc) wishing to transit from the plethora of strips to the south and west of Sydney, to the central coast and beyond without having to tackle the tiger country behind Richmond. We have all seen how the use of radio can and does improve situational awareness, and in this situation with the proximity of the SY and RIC CTR's, a dedicated frq IS the answer .
What then? An MBZ would be nice I grant you that, but that only leaves a CTAF as the only other option. My feeling is that the LOE does deserve a frq of it's own purely due to the amount of traffic it handles. Can someone please remind our "Safety Authorities" that "Safety" is the primary flight concern of just about everybody?
Regards,
4/J