Found a possible plugin solution as you said, @boston85719. @ahmadnaser16an just released a great plugin (Selected Text) that not only supports custom menus but ALSO includes highlighting text, which is exactly what I wanted.
Found a possible plugin solution as you said, @boston85719. @ahmadnaser16an just released a great plugin (Selected Text) that not only supports custom menus but ALSO includes highlighting text, which is exactly what I wanted.