It’s mentioned plenty of times but probably not in a concise format. Essentially you’d only need to use it if you have issues with the game minimising itself from full screen, and/or you specifically want to use windowed mode but with the same appearance as full screen mode. In my experience proper full screen mode runs much more smoothly than windowed (due to vsync control, which is a whole other topic), which is why I don’t think Borderless Gaming needs to be recommended for everyone. If that makes sense!