Thanks for your interest Boogz.
I went through the concept with a VASS engineer; the NCOP (which Vic has adopted now and NSW is not far behind I believe?) pretty much shuts down any possibility of this concept being 'legal', and by the sounds of the responses here, if it's not fully engineerable the market is greatly reduced.
I'll keep talking with different VASS engineers to see if somebody has a more flexible opinion. For now though, consider it off.
Still doing the wide flares though.