"We have built UNA to make establishing an online community easy - no coding needed, no update dramas and no massive development cost." -Andrew Boon
UNA has moved away from that statement a bit. Both RocketChat and JOT Messenger requires one to install the servers for those applications and to configure ports on the server to handle them. I would say for most, they are going to need to hire a developer to handle these tasks. Even the push notification requires some installations of files although most should be able to handle it without a developer.
I have no problem with Boonex seeking third party applications to expand UNA and it makes good business sense to do so. Why invent a new messenger app if a good solid one already exists? I would caution against using any third party application that is not open source because without it being open source, UNA users could face headaches down the road if that third party application becomes paid or even just disappears. With open source, UNA users will always be able to continue to use that application and even to modify it if necessary.
Maybe it was inevitable that UNA would have to move away from being a plug and play solution.