Maybe I misinterpreted your question. What is the part of the menu bar that NoMachine wants to occupy? Is it the !M icon in the notification area? This is a security measure used by the server, indeed to notify you about connections and also to let you check at any time who’s watching your screen while you are working. It is also used to access screen recording, something you probably want at hand when you need it.
If you only use the client you can disable the server part using the admin GUI.
To check if it is disappearing try:
sudo /Applications/NoMachine.app/Contents/Frameworks/bin/nxserver –shutdown
If this is what you are talking about, we didn’t consider, honestly, that the icon in the notification area could be so obtrusive. Good to know. Probably there should be an option to hide it. Of course at the cost of some functionality loss, but after all the user is king.