Is this a TeamViewer/AnyDesk level of interactivity or just a Twitch level of interactivity from 2nd screen? As in 2nd screen can be used to control the main source screen or just to watch what happens there?
Works the same as an additional monitor- which is what it is. The Dummy Plug creates the second monitor thru native support in the OS. Deskreen connects your additional device to it via a web browser. I installed it on Ubuntu and had it working in two minutes, using my iPad Pro 12.9” as a second monitor ;-) Looks and works good and decent latency.
can that second monitor be controlled with the mouse and keyboard from the device where the browser is running?
I tried and I couldn't.
indeed, i tried it myself now. but there was something in the wishlist of features about remote control. it should be possible to capture mouse clicks and most keyboard input in the browser and send it back. don't know how much effort that is though
Twitch does the same. Run Twitch in browser and broadcast with OBS your main screen. Then any device can see your main screen
The main issue I see here is the interaction on the "customer" side. There are too many buttons to click.