Mandate transponders in MBZs (yes, renamed from CTAF Rs 
).
How about 'we' mandate certified TCAS systems in any aircraft 500kg and up, capturing all RAAus aircraft. 'We' could also mandate mandatory airline style TCAS training to all pilots as part of the licencing or certificates.
And how about 'we' mandate vertical self separation between departing and arriving aircraft..........hold on.........
And how about 'we' mandate the IFR traffic parameters to 16 minutes, because a full 16 minutes will give you time to come up with 'I'll climb to 4000 if you want to descend to 5000 until centre tells us we're clear'