dmNavigation has never had an approval process. I've yet to use any
of the 5.x branch but I assume not a whole lot has changed. I know
security was scheduled to change though. On my 4.0 branch, you can
simply do this...
log into the webtop as an admin and find the node that you want to
restrict. Right click on it and select permissions. Change the
select box to the permission group you want to modify ("contributor"
in this case) and for "Edit" change it to "No".
This will keep them from getting the move menu completely.
If you want to know more about what else would be affected, look at /
core/tags/navajo/overview.cfm (this was around line 1244).
NOTE: This is on version 4.0 as I mentioned.
-Jake