As usual, the tax Q is confusing. I believe the ATA have changed the ruling on non-residency within the last couple of years.
I am told that as long as you have the slightest interest in returning to good old Oz, you will be liable for tax on return.
I should imagine that most Oz EK drivers intend to come on home when their stint in the sand pit is done.
The trouble is that the experts in Oz tax law seem to have slightly different opinions.
Maybe the answer is to buy up heaps of cheap rugs as a hedge against that possible big tax bill when ditching the sand pit. Or, god forbid, retire to NZ. Great spot apart from the Kiwis
Good luck.