To use multiple Audio Outputs at the same time on Windows 11/10, follow any one of these methods: Utilizing Stereo Mix and multiple Playback Devices Using Voicemeeter Try both of them to understand ...
My cheap-ish Samsung (cheap for a QHD) has an HDMI and a DisplayPort input. If I hook up a laptop to each input, both laptops think the screen is on- even the one who is not currently being displayed.