The problem, children, is that you need to understand the way CASA is capable, as evidenced by AAT records, of dealing with someone who they decide to punish.
If CASA had the trust of the industry, which they do not have, as evidenced by the Forsyth review, then a 30 minute rule would be non controversial. However CASA AAT transcripts show that CASA will go to almost any lengths to "get" someone they want.
Thus one has to assume that a CASA rule of 30 minutes is ironclad. It doesn't matter if its 29.5 minutes and you are CAVOK and on final approach, they will 'get " you if they want you. That is clear from AAT hearings when they even argues that a taxying gyrocopter was flying. There is no room for common sense in CASASpace.
To put that another way, CASA will treat the pilot of a C150 exactly the same as a B747 driver if they transgress that rule, in fact the C150 pilot will be treated worse since he doesn't have a union or an employer to support him.
The risk here is that various posters think that the rule will be applied with common sense by CASA although experience (Forsyth review and AAT) show that this is not the case.
For that reason I submit that this is bad regulation that will have counter productive safety consequences.