Using SeaBIOS it is possible to remove chromeos and install a GNU/Linux distribution of your choice. For security research Kali Linux is the standard.
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Pro Gives you the full power of Linux
in going with this method, you will get the full power of Kali Linux (or your distribution of choice) depending on your model of chrome book the driver support may vary. You will have to research your model of chrome book and Linux distribution of choice to verify everything will work out of the box.
Con You will void the warranty in most cases
Almost all of the official google chrome-books (See C720 series for an example) have a hardware write screw to protect the BIOS, To install SeaBIOS you will have to remove this screw, and in doing so you will void the warranty on your chrome book.
Con Removes Chrome operating system
If you go this route, you will lose access to the chrome os. It is not possible to dual-boot chrome os and GNU/Linux. Therefore if you would like to have the possibility of using chrome os in the future you will need to make a backup of the operating system.