Based on what's been presented, there could surely be no safety recommendations beyond what CASA, ATSB, and every school and instructor ever says...DO NOT FLY INTO IMC IF YOU OR YOUR AIRCRAFT ARE NOT SUITABILITY EQUIPPED OR RATED.
You can be caught out whilst airborne and the PIC may be able to offer some kind of reasonable explanation, but to make the decision to launch into it from the ground really is inexcusable.