[B]ut it is already annoying in the circuit in Northern Victoria to have to listen to calls from CTAFS hundreds of miles away who share the same frequency. One wonders how annoying the area frequency will be if it gets cluttered up.
You have Dick's proposed system the wrong way around.
But it makes little practical difference.
If 126.7 becomes the quasi-Area frequency for low level ops, it will theoretically become even more annoying because calls that would otherwise be made on Area will be made on 126.7. I say "theoretically" because the number of calls made on Area by aircraft operating in the vicinity of strips that aren't marked on charts is 0.001% of Area frequency calls.
Either way, it's
never going to be "beautiful silence" on 126.7.
If you have Dick's preference for "beautiful silence", you're better off not fitting a VHF to your aircraft and confining your flights to places at which the carriage of VHF is not mandatory.