This putting a pulley under the desk and sitting in a chair is too restrictive for me.
I use a Bungee in a standing position. I get the best flexability of any kind of setup this way because I can do SO, SU and leg overs left and right. Add to this fulcrums from any one of these positions and your ligs don’t stand a chance. I get enough SD’s with my Rings so I don’t even go there for exercise.
I can increase weight at a moments notice and I can decrease weight quickly and safely. I don’t have to deal with metal or any other kind of static weight.