I suspect I have to notify something or run the kicker script, but I
can't seem to find anything that really states what I should be
doing and so far experimentation has produced no results.
I did read a few years back that scutil was not recommended to make
a change like this (to the persistent data store). So I'm also
wondering if that is still true. Should I just stick with ncutil?
(I'm trying to reduce the extra requirements of some management
scripts I maintain, and reducing the requirement of ncutil would be
a nice one).
The scutil commands (that you've noted) do not change the persistent
[data] store. They do make changes to the dynamic [data] but will
a) be lost whenever configd gets restarted
b) be overridden if the persistent store is updated via network prefs
To change the configuration you really need to use an app/tool which
modifies the persistent configuration (like the network prefs pane,
like ncutil, ...).