CASA have been aware of these issues (contiguous airspace) since the AsA industry forums last year. As per usual they put their fingers in their ears and said to ATC and pilots - you work it out.
The issues isn't just IFR to IFR seperation, also special VFR to IFR seperation. VFR can no longer simply remain clear of cloud, and any change to special VFR while there is a 'jet overflying on the ILS' will lead to being held OCTA. The pilot starts holding OCTA, in marginal weather around a busy aerodrome, and we're opening ourselves to another mid-air.