how to move some overflow toolbars to a new window, or any best ideal for temporary keep those toolbars

Not sure what you mean. Are you talking about Tabs that you want to move ? You can select multiple tabs and move them to a new window via the Tab bar context menu. *https://support.mozilla.org/en-US/kb/tabs-organize-websites-single-window Can you attach a screenshot? *https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem *use a compressed image type like PNG or JPG to save the screenshot