I just access the soldering iron tip through the coils of the stand without repositioning. The coils are separated enough so that the tip is relatively accessible without risking the iron falling out of the stand and burning/melting something. I also turn off the iron whenever I leave its immediate area, but, that may be too cautious for some. Ordinarily, the third hand idea positions what is to be soldered, rather than the soldering iron. Such fixtures with clips, springs, etc for holding components and wires are readily available.
I enjoy the use of an old Weller TC201/TC202 as might be what you picture.
