Hello @manymanyhaha!
Here is a video that shows how this mode works.
You need Ableton to send the vumeter information as CC on channel 16. This can be done in a few ways, for example remote scripts, a dedicated MAX device, or a combination of both.
For both we have something you can try.
This is a Max device
This is a Max device (262.5 KB) made by @nacaramusic.
You throw this device in a MIDI track and set the output to send messages to channel 16. Previously you have to make sure the MIDI port is set as Track output in the preferences
Then on the device itself you can set which track sends which CC.
The other option you can try is the Universal remote script we developed for our controllers. In the User guide you can find information on how to enable it the VUMETER feature.
This feature is in really early stage, so if you want to test it and give us feedback, it’ll be good for us.
Hope this helps!
Let us know if you need more assistance 