Deactivating 1 of 3 video outputs temporarily without Kwin / X noticing it

I’m looking for a way to temporarily deactivate the video output to my main monitor (HDMI on a GTX 960) to force it looking for another signal so it changes to my Win10 Gaming VM’s Displayport signal.
Technically it’s an easy task with xrandr, but I want to do it in a way that neither Kwin nor X notice’ it, starting to reorganize all windows on my 2 other screens, only to reorganize it again 3 seconds later when the main screen comes back, completely screwing over all my open windows.

Used to have a physical button on my main screen that changed from DVI to VGA input, but I recently upgraded to a way more modern 1440p 144hz display where I have to maneuver through menus with a tiny joystick to change the used input. Looking Glas also isn’t really an option for the sake of performance and minimized input lag.

I’m using Arch Linux with X + Kwin/KDE. GTX 960 driven by proprietary drivers (again for the sake of performance, nouveau still doesn’t support VAAPI / VDPAU on the 900-series and I really like my fancy video wallpapers). Screen is an Acer Nitro XF272UP, connected via HDMI.

Anyone got an idea how to make sth. like this work? Any idea is highly appreciated. :blush:

I am not sure if it is even possible to do that, since you are basically asking for a way to turn the actual port on the card which is outputting the video signal off.

 

Edit

Is this kind of what you are looking for: https://superuser.com/questions/1286706/how-to-disable-hdmi-port
If so, you are most likely out of luck. Sorry.

Also, is it possible to create a shortcut on the monitor itself, since the option is already present in the menus?