The qpwgraph workaround works in the matrix clients as well, but passing media audio into a WebRTC stream meant for voice is not ideal. Any decent client is likely to heavily filter out background audio (which with a game would be a lot of the ambient soundscape), and the audio would in some cases end up mono.
Broadcast-box is on the simpler side, if self hosting. If not, there is a public free-to-use instance here: https://b.siobud.com/











I usually go with Kubuntu.
Set up flatpak, share internet from my phone via usb to install broadcom wifi drivers, and modify the KDE desktop to work more like MacOS (add top bar with search widget and alt menu, turn bottom taskbar into a dock, move window buttons to top left).
Hand it back to the post-MacOS-user. No complaints so far. In fact one came back with another Mac and asked me to do it again.