Rated 5 out of 5 stars

A great addon.
But, can you make it possible to move site search engine outside of the submenu? If so, when I select a word or words and right click, site search can be done with more convenience.

Thanks, lwz. By following your instruction, I made it successfully. 1) select an engine, google for instance; 2) tick site search; 3) tick outside of submenu

This review is for a previous version of the add-on (0.4.6.8). 

It can be done with the current version... You configure the "site search" item by first clicking on the "Site Search" radio button (or option button, whatever you call it), then clicking "Context Menu" and selecting "Outside Submenu".

Very useful addon Rated 5 out of 5 stars

very useful, thanks a lot.
But, how can I move a specific search engine outside the submenu? I tried my times, but failed.

This review is for a previous version of the add-on (0.4.6.3). 

You could just use the GUI as pictured in the second screenshot. To access the GUI you can (1) click on options for Context Search X in the Add-on Manager (2) click on the icon of the current engine in the search bar at the top right and choose "Manage Search Engines..." (3) select some text, right-click, and choose "Manage Engines..." in the Context Search X sub-menu.
To use the GUI you click on the engine that you want to configure first, then you click on the button "Context Menu". Then you can click "Outside Submenu" if that is what you want. If it doesn't work, it is a bug. You would have to tell me the version of Firefox you are using and what other add-ons you have installed.