I have two instances of freepbx installed for over a year now - one of them is in standby in case the other goes down. Freepbx is a great piece of kit and minimal on resources. I find it great that it is being incorporated into the NS but I would be concerned of it sharing resources with other applications - is it possible to isolate or allocate dedicated resources to asterisk within the server so quality doesn’t drop if the VPS is under strain from other apps?
Another project I would like to see incorporated into NS is turtl - https://turtl.it/ - Its a secure sync server to host notes, pictures and other clips. I’ve struggled to find a secure self-hosting application to host specific information which I only want to be accessible by me and that it is kept encrypted while stored and transmitted. turtl seems to be a great implementation of this idea. Moreover, the project is hosted on an it domain, which leads me to believe the core project is based in Italy (as Nethserver ?)
A final suggestion for another project I recently came across to implement a chat client that can make use of the XMPP server in NS - https://www.jsxc.org/ - They have implementation for owncloud and SOGo (which I’m currently using) and I thought it could be an interesting chat client to incorporate into NS (or the owncloud/SOGo apps within).