For What Are Poros Herded?

In the latest Ask Riot, Scathlocke wrote that “For many weary inhabitants of the Freljord, retiring to greener pastures and becoming a poro herder would be a dream come true…”

Poros cannot be eaten, since a much earlier Ask Riot has confirmed that eating Poro meat makes you a Poro. That constraint on traditional herding purposes leaves milk and fur. Can Poros be milked or sheared or, if not, then for what are they herded?

Also, since a group of Poros is called a fluft, would a herder not instead be called a ‘flufter’?