I would disagree with the approach brief single-pilot. I agree entirely that it can prevent using the wrong plate, but in the training and the test there is no actual danger in using the wrong plate, the instructor or examiner will prevent any hazard. The instruction and test are designed to make you safe in an operational situation. Last time I used an ILS I could not brief: my passengers would have been disturbed, I think. There was certainly no-one else up there who could have taken any useful information or given me advice. How many people brief in operation an approach if there is no second crewmember? If none, why train like this?
Under JARs the aircraft-specific systems come into the class- or type-rating training, as would your prop overspeed drills. They had obviously been badly-trained, as that should come into training for complex single or multi-engine aircraft in the CPL.