I have checked out some of the DIY capacitive pens but none of them have any elegant means of producing a fine tip s-pen stylus. I have played with note 2, 3 and note pro pens. Even tried a note 1. I even did the insertion of the note3 pen into a Bic Pen sleeve to provide girth to the pen.
Those of us who do technical design or any kind of drawing on the note pro have been suffering with that miserable excuse of a pen that Samsung provided. You would think that Wacom or Pentel or any company in the field would properly address this issue.