My 2005 Ducato has also developed this fault of late. 'Your' explanation is an excellent one given that it is thoroughly researched, evidence based and provides a ready solution. Slightly puzzled as to why it has taken 5 years to manifest the glitch though.
Probably linked to a plethora of diagnostic elements for the ECU.
You got me thinking Ray.......Got this from Google
A crank sensor is an electronic device used in an internal combustion engine, both petrol and diesel, to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters.