Cool. I have a few questions:

How many people can you have in sessions simultaneously?

Do you use the shared whiteboard? What's it like for people without a stylus?

Any idea why it requires such an ancient version of Ubuntu (16.04)?

That readme is 17months old. and the reference to 16.04 is atleast 3 years old. So it may just not have been properly updated.

Taking a quick look, this should be able to run without issue on any distribution. They're using Docker to run all the components. No Ubuntu-specific dependencies.

Do you have some numbers what capacity one needs for this many people? Is it webrtc? Can you have more than 10 in a video call?

Several schools in the US are using this for online classes in the face of COVID-19.