Yeah,
I couldnt live without it either, I write all my code by hand, tinymce is good but I can do it a lot faster by hand.
I trawled through the js and css, removed some functions 1 by 1, ran editarea, checked it the highlight was disabled, and put back in the functions if they had no effect (so I put back in all the functions

).
I can live with the highlight, and it’s such a great piece of software I can’t really complain, I just tend to make fewer mistakes when I can see the coloring of the line I am editing.