I am by no means an expert on electronics. The most modern plane I ever got to feed my desires on is a B767. Back in the airforce, way back then I as the Mil Spec 1553 was new couldn’t believe what it can do. That thing is like a Volkswagen now. Over the years I had the plaesure to talk and fly with a few Boeing test pilots. Their logic about the data buses is that it can get so complicated, they don’t want you to dick with the logic. They can’t possibly provide documentation for every single possibility that might arise because of the bus interaction with stuff. They expect the training departments to be capable of teaching their pilots enough about the airplanes to deal with scenarios like being able to turn things off. Now I flew a B727 as Captain for about 10 years in cargo and their wasn’t a taining event without a trim runaway or freight shift scenario. The cutout switches had some status. Since I fly the 76 I have not done a single such events which does malke me wonder.