I do not have S-Off but can flash ROMs and switch between Sense and AOSP images. What do you need S-Off for?
Here are more supposed ways to get S-Off but as always it is not to be taken lightly and I have never tried these processes...I cannot vouch for them.
http://rumrunner.us/
http://moonshine.io/
Just tried rum runner and same thing. Going to try flashing a different rom to see if that will work.