Rule of thumb: Apple will not trick you into fouling-up your system. Other developers follow suite. If you need to restart your computer, then you will know it. The Installer will usually not give you a choice. You will be forced to restart immediately. There are some installers that will give you the option of restarting later. However, if the installer does not force you to restart or does not give you the option to restart immediately or later, then there is simply no need to restart. Doing so is a waste of time and serves no good purpose.