These are only for more advanced users with at least some experience with technology, coding, or Chromebook exploits. If you do not fulfill this criteria, I highly suggest you do not attempt these, or find a friend to help you. You will also require some patience to try these. With that being said, these really aren't that complicated once you try it. Good luck!
Previously, the Alohomora exploit was locked to only one window. However, through some clever usage of Javascript and Bookmarklets, this problem was solved, albiet in a slightly complicated and hacky way. You are able to create more than two windows, but creating a third window will prevent you from accessing your first window using Alt+Q until either the second or third window is deleted.
Type "about:blank" into the URL bar. This will create a blank page with nothing on it.
Type the following string into the URL bar: "javascript:(function(){window.onbeforeunload=function(){return '';}})();". If you paste the string into the URL bar, Google automatically deletes the "javascript:" portion of the string, so you will need to retype it. Press enter.
Right-click the tab, and click "Move to new window" in the pop-up that appears. A new window will then be created. Finally, click "Cancel" in the popup that reads "Leave site? Changes you made may not be saved." Don't click "Leave", as this will close the window. Congratulations! You have now created two windows.