Triple buffering is triple buffering as far as I know. The Windows desktop manager doesn't do anything different. The only reason to use borderless fullscreen for triple buffering is if the game doesn't support it, and you can't force it through RadeonPro. Furthermore, the Witcher 3 is using triple buffering which can be seen at all the moments when the framerate goes below 60, as it scales normal (eg going to 55, 45 whatever( instead of fluctuating between 60 and 30. That cannot happen unless the game is triple buffered.