The answer is maybe to auto merge what has not changed locally? To me, changes to the boot process is just as interesting as changes to the default shell settin

The answer is maybe to auto merge what has not changed locally? To me, changes to the boot process is just as interesting as changes to the default shell settings. The distinction between configuration and code isn't what's important here. The purpose of these files are to describe a system wide default state. It is not to mark them as devoid of programmable logic. The latter doesn't even make sense if you look at what else is there. /etc/profile for example is clearly code.