Hi Yellow, and thank you for this great Module.
This feature they want is exactly the way Magic SEO URL, a paid seo module for zencart does. Now, let me admit that Magic SEO URL is superior than SSU in some fields, but it is a matured product (developed for a while), and it has its own drawback too.
It support only core links, that mean links generated by the modules you installed are not seo link at all. And even some core links are not fully supported.
I like it just as it is. I know some people want things differently and please don't take this the wrong way, they should pay you for changing the code just for that purpose or go buy the Magic SEO if it will do the things they want. Everyone doest need to remove those special characters like me. Thats the way I see anyway. Good Module Yellow.