Interesting information, thanks for sharing. Definitely doable by adding also the monitoring module, which would show you associated clients in a chart.
But it's not as easy to set up as Ubiquiti though. I hope in the future it will be.
I think you are wrong. I have been working on https://openwisp.org for some time and implementing a controller which is robust and can handle many different corner cases and offer good functionality and also ease of use is a challenge and requires several people working full time on it. Even simple functionality it's a lot of work, unless for simple you mean really trivial. If it wasn't hard, there would be many alternatives but as far as I know there aren't many.