I have printed the report but not yet read it. On first glance, I suspect that the ATSB has side stepped the more difficult issues that might have delivered some lessons.
Top in my mind, is that I can't imagine a pilot who has been dealing with an issue for several minutes and has a descent rate that knows is a problem is not going to push the throttle forward at some point. You might start out trying to be nice to the engines, but at some point I struggle to believe that desperation won't kick in and you'll push everything forward. I'm expecting to see some gaping gaps in logic from the ATSB here.
I disagree with the EMS bit. It wouldn't have changed a thing. The experience of the engine surging is going to over-ride what any instrument says. Either you can deal with the engine misbehaving to gain whatever residual power it will produce or you wont. EGT's can't help assess that.
We tend to think of aircraft fuel injection as more complex than it is. It is what the car racing guys call "piss & dribble". The injector is a brass fitting with a hole in it. It continuously sprays fuel into the inlet manifold at the back of the inlet valve. I'm going to read the ATSB analysis of this with interest.