Thanks Grem that is all what I was trying to say. That the points raised by John had already been discussed.
As I also wrote, even if one moves the non-required midi tracks to a folder, and then only selects the rest to be saved, the ones in the folder still get saved.
Cake have simply implemented the GM1/2 specs re this. Correctly too. Users are aware and simply temporarily remove tracks or save a separate file to maintain all original data in storage should it be required again.
In my case I save all my midi projects as a CWp, then open that remove the tracks I don't want then save that file to the "working" midi for use elsewhere, on a gigging keyboard for example.
This method is nothing new and I am sure many other Cake suers do the same thing.