Yes. I also understand the UK has notified a difference with ICAO stating radio is not required for IFR in class G.
It obviously works with high levels of safety and would result in less forced risky scud running as happens in Australia where full flight plans details must be lodged with the government if about to enter IMC.
There are times where it would be safer for an Australian IFR qualified pilot to enter IMC - even for a few minutes- in uncontrolled airspace however there is no procedure to allow this without a full IFR plan being filed with ATC. Now that Flightwatch has been closed such a plan would most likely have to be transmitted on a frequency that was also being used to separate airline passenger aircraft. Not an ideal system.
And can someone confirm if a transponder is mandatory in class G in the UK ?