In Chrome, when typing a search into the Omnibar, I can user Cmd+Enter to open the webpage or search query in a new tab, with the tab immediately being backgrounded -- this way, my focus stays on the current page rater than switching tabs.
In Firefox, I can use the similar key combination Ctrl+Enter to open a search or URL in a new tab, but the new tab is immediately focused.
Is there a key combination in Firefox that lets me mimic the backgrounding behaviour present in Chrome? Additionally, is there any way I can bind this to Cmd+Enter?
My operating system is OS X.