Settings only work for files generated by extension?

[CrispyDrone]

I've added these to my user settings:

{
    "csharpextensions.useThisForCtorAssignments": false,
    "csharpextensions.privateMemberPrefix": "_"
}

This works in C# classes that are added by using the extension functionality, but when I add a parameter in a constructor of a C# class that already existed, it refuses to work according to my user settings.

Is this expected behavior?