Request Feature ... Rated 5 out of 5 stars

- Add option (check box) to show/hide context menu item ...

Thank you ...

This review is for a previous version of the add-on (2.2). 

I'll add that in the future; workaround

I do plan to add an option for that; you can track the issue here:
https://github.com/dadler/thumbnail-zoom/issues/90

In the meantime, a workaround is to install the Firefox add-on "Menu Editor", which lets you hide that menu item.