Thanks for the info.
I found an interesting thread, it seems like it is possible to force exclusive mode using command line parameters.
Windows: Added a new command line argument for standalone builds: window-mode. Options: borderless, exclusive. It lets users override the default fullscreen window behavior.
Pass -window-mode=exclusive and enjoy adaptive-sync on any Unity game built on 5.3.4."
You could try that and see if it solves your screen tearing problem, and perhaps also makes it possible to use 3D.