This lead only drops from psijic portals in Southern Elsweyr. I spent over an hour today looking for portals there and couldn't find even one. Harvested SO many runestones. The portals are so rare, it would seem more reasonable for the lead to drop from runestones as well, even if at a lower rate.
Most mythic leads you can do the activity a couple of times a day and then try again another day if it doesn't drop, but this one there's no way to guarantee even one chance a day without hours of work.
Anyone got any tips for a console player (so no add-ons) who is about ready to tear her hair out?