Dewcon - interesting post.
I’m not in possession of all details, but I think that ML has stuck with the initial issue software/hardware configuration for the life of their detector models, except for the 1 update for the CTX.
This makes some folks happy, they don’t have to worry if they have the “latest and greatest”.
Other companies seem to revise the software and probably hardware as production of a given model goes on. the good news is it it often an improvement - the other news is folks start obsessing about whether they have V 3.2 or V. 4.0, etc.
Most companies, somewhere in their published material state that they reserve the right to update specific items included in the production of a given model as production continues. I know that my Honda Civic had a change in a suspension component during a model year and they had to run my VIN to find out which component my car had.