Black Forest and the new Planning Code

I spoke at length yesterday with planning staff about the effects of the proposed new planning code will have on Black Forest and Clarence Park (west of East Ave). This area has been included as a General Neighbourhood zone with no heritage overlays that most of the rest of Unley will enjoy. A higher level of protection would be afforded if the zone was considered to be Suburban Residential as a Technical Numeric Variation (site area) would be allowed. The current zoning for the entire area is 350 square metres  per block, the new zoning would be  reduced to 300 in most areas and even allow for row housing with 200 allowable. The other concern, and  this is across the city, is that new development will be able to be approved by private certifiers. Despite continued promises that these people could only approve if the development proposal met the Code in every way, we are now told that near enough will be considered good enough and that approvals can be given if they are not considered to be seriously at variance. Given that recent approvals have indicated that 285 is close enough to 350 I wonder what will be close enough to 300?