considering the traffic densities, the speed of new aircraft and the traffic mix ... it's time we enforced indicators (ADSB Out)
Gets us back to quantifying this statement doesn't it.
It has been said that there is always the POSSIBILITY of a mid air crisis, but what is the PROBABILITY?
To date everybody has an opinion as to how concerned they are, near misses, near hits or whatever, but nobody has been able to QUANTIFY the RISK except use anectdotal dreamtime stories of how they failed to look out the window in VFR.
Let me put this into another frame: I believe, as you, that ADSB will be a natural evolution of the present radar coverage and probably beyond. I will embrace this evolution just like I have the new ELT. However in Class G airspace in the GAFA ADSB is an answer to a problem that doesn't exist.
Show me a quantifiable risk in G, facts and figures, and I may change my mind. In the meantime the use of this equipment below FL290 is only an annoying dream of a few who know it must be mandated to achieve optimum perfoprmance as anything but a tool for the benefit of Airservices.