In game settings, when you select “full screen”, it has no effect and actually uses windowed full screen (not true fullscreen). I could tell this, because alt tab would not allow me to tab out like normal. You can verify this in the CVARS file. Regardless of what setting you choose, game or manually overwriting in CVARS, after starting the game it will overwrite the CVARS window value of “3” which is for true full screen, and change it to “2” which is Windowed fullscreen. Every previous version of destiny two allowed you to select true full screen and tab out. You can’t even override it in CVARS. It’s no longer supported.