The problem is I think that they are using moonlight which is "designed" to stream games at very low latency. I very much doubt that people need <30ms response times watching an agent terminal or whatever they are showing!

When you try and use h264 et al at low latency you have to get rid of a lot of optimisations to encode it as quickly as possible. I also highly suspect the vaapi encoder is not very good esp at low bitrates.

I _think_ moonlight also forces CBR instead of VBR, which is pretty awful for this use case - imagine you have 9 seconds of 'nothing changing' and then the window moves for 0.25 seconds. If you had VBR the encoder could basically send ~0kbit/sec apart from control metadata, and then spike the bitrate up when the window moved (for brevity I'm simplifying here, it's more complicated than this but hopefully you get the idea).

Basically they've used the wrong software entirely. They should try and look at xrdp with x264 as a start.