Biggus
One of many perceptive posts....
Correctly documenting it, preserving configuration and especially thorough testing is the cinderella part of the industry that it is difficult to find anyone who wants to do.
In 1987 I inherited all development, production, repair and PDS activity at a certain well known company. They had only one such software engineer covering the activities you list, because it was so difficult to find anyone. He was a Type 2. His wages were paid entirely from the MoD PDS contract, which covers the configuration work you mention and, ultimately, maintains the Safety Case.
In 1992, when the RAF Chief Engineer directed that such activities were to cease forthwith, and slashed funding, the company had no option to give him notice of redundancy. He was in the middle of doing a safety upgrade to Sea Harrier Nav Systems. I moved heaven and earth, transferred money around, cancelled lesser priority contracts and sold my mother to keep him in a job. I told the company to book his hours to something else. When the CE’s lackeys at Harrogate sought confirmation the work wasn’t being done, we all lied through our back teeth and assured them that, as instructed, the work wasn’t being done and the kit no longer safe.