I think that one of the reasons the IAM and Bikesafe are sometimes criticised is their apparent rigidity in sticking to the "system". My dad was a senior police officer and as his crew all had to have Class 1 police licences as they hurtled about County Durham in souped up Triumph 2.5pis he decided he should also pass the test. He used to come home shaking after various training sessions which had him overtaking round blind bends and all sirts of what the normal person would consider lunacy - all protected only by flashing blue lights and 2-tones! I have his certificate on my wall.
He taught me to ride and drive and I passed the IAM bike test in Brum in the 1990s, out of the Aston police station Martin mentions. The only adverse comment made was "You could have passed that car on the roundabout entry" - ie make progress at all costs. An approach which I don't think is useful for the normal rider.
The system and Motorcycle Roadcraft were still being used as the basis for all training at that time and by the sound of it still is. I think as well one of the problems is that police officers are rarely trained educators so often don't have the skills needed to pass on the necessary.
In my view, what os far more imprtant than either technical bike handling skills or even the various acronyms used by some training organisations (which I can't even remember) is having the right attitude - something which often seems lacking in many drivers and riders.
There are trainers who are much better in my experience. I did an assessment with a chap called Kevin who runs a company called Survival Skills -
https://www.survivalskills.co.uk/about_us.html - and found his approach very helpful.
Sorry the above is a bit random - still suffering post viral fatifue I think.....