Just thought i'd share this in case anyone will be looking for the same thing in the future; how to stream QW in windowed mode. The benefit of this would be to get rid of the stream freezing for your viewers whenever you alt-tab out of the game. Also the in-game sounds will still play. The vid_borderless command will still make it look exactly like you're playing fullscreen though.

Command line:
ezquake-gl.exe -window -width 1920 -height 1080 +sys_inactiveSound 1 +s_restart +vid_borderless 1 +vid_xpos 0 +vid_ypos 0 +_windowed_mouse 1

After launching ezquake with above commandline, do a vid_restart for the borderless mode to take effect:
vid_restart

Should probably make sure to move the windows task bar and any other open window (web browser, file explorer etc) on the screen you'll run ezQuake on, to a second screen, before you run ezQuake. With stuff open in the background it will disturb the ezQuake window. You can get rid of this by setting vid_borderless 0 but then you'll miss 1-2 rows of the console as it will be taken up by the title bar(?). If background windows starts messing with ezQuake then you get back into the game by pressing the ezQuake icon in taskbar (sounds more obvious than it is :p).

How does the affect the hardware gamma of EzQuake?

In-game QW got darker. I didn't try to fix/tune it though and it still looked ok on stream i think (where i have 1.5 OBS gamma).

Can't seem to alt-tab or minimize with borderless hmm...

- the /windows command seems to work as an alt-tab, but then recording goes black.

Hey Ake,
+vid_borderless is not working anymore... Has it been dropped ?

It should be now vid_win_borderless

See ez commit