Jitsi with Jamulus audio

I sing with a barbershop chorus (choir) based in the UK. For several months during the lockdown we have been using an open source application called Jamulus. This is client/server audio streaming software based around the OPUS codec. Forty of us meet weekly on Jamulus. Unlike Jitsi audio we can all hear each other all of the time and because it is low latency we can sing together in real time. We use headsets to avoid acoustic feedback. Recently I tried installing a Jitsi server in the same data centre as our Jamulus server. Amazingly lip sync with Jamulus audio was very tight! Not perfect (a single clap of the hands shows slight video lag) but not noticeable when singing. We also found that we could follow our conductor quite easily and achieve good synchronisation. For us, adding video to Jamulus is game changing. It does, however, lead me to seek some advice.
The first thing is that as we are not using Jitsi’s audio at all, is there a way of completely disabling Jitsi audio so that not only is audio not streamed (saving bandwidth) but also so that Jitsi does not try to use audio devices that might be needed by Jamulus? So far all I have found is a setting in config.js that forces audio to be muted when a user joins a room (startWithAudioMuted: true,).
The second thing is how do I minimise bandwidth usage for users with limited internet bandwidth. The only setting I have found that seems to do anything is as follows:

resolution: 240,

constraints: {
    video: {
        aspectRatio: 16 / 9,
        height: {
            ideal: 240,
            max: 240,
            min: 120
        }
    }
},

This setup limits video quality along with bandwidth (as expected) but also reduces CPU load by the browser. This helps users with slow processors.

I have tried to manipulate the following but they don’t seem to do anything:

opusMaxAverageBitrate: 6000

    maxBitratesVideo: {
        low: 2000,
        standard: 5000,
        high: 15000
    },

Is there a way of forcing tile view when a room is joined?

Finally is there a way of recording video locally?

Any advice would be welcome and appreciated.
Thanks.

The constraints you set for your video already do the job, so no need to worry about the maxBitratesVideo property. That property basically sets a limit on the maximum bitrate to allow per resolution definition; this likely won’t have much effect in your case where you’ve already reduced your resolution to the minimum.

In the current stable version of Jitsi, this happens automatically once a 3rd person joins a call. Also, your browser remembers whatever setting you set the last time; so if during your last meeting you set the view to tile, your next meeting will start in tile.

When you say “locally” do you mean on the server or on the client (computer or mobile device)?

Thank you so much for answering my questions.
By “locally” I mean on a client (windows 10) PC using the newest version of Edge.
Thanks.

Not using Jitsi. But I’ve seen a screen recording app somewhere (RecordRTC or something like that), that you could look into.

Thank you.
So is video recording available on the server?

Yes, you can deploy Jibri to record to the server - TUTORIAL - How to Install the NEW JIBRI

Thank you.
I think this is my final question:
Is it possible to completely disable audio on Jitsi so that it does not stream audio nor try to access audio devices in use by Jamulus?