150 or 2000 hours - It's still a commercial job and should require a commercial licence to be held.
The hour requirement and low time instructors is another issue which i hold strong feelings about but this is not the topic for them at the moment.
Just make them get a commercial licence
If you're good enough to instruct then you can pass the CPL flight test - simple - argument over - amazing that CASA even have a discussion paper out on it.
Do we want GFPT holders to do local commercial flight just because it may fall into a 10nm radius - I dont think so - So much for CASA looking after the travelling public. Not only will we have people with lower and lower experience levels flying things with burners and heaps of passengers, but they wont have even been trained by a Commercial Pilot.
If it wasnt such a serious issue a guy could break down laughing