Completed tasks in "my overview" currently only show "personal tasks" and not all "my tasks".
It's okay to have a "personal tasks" feature, but Its currently not very intuitive. My suggestion is that "completed" tasks reflect all my completed tasks whenever its a personal or a assigned task from a kanban across work spaces/projects.
Silvija Donceva
For Q1 in 2017 we don´t have any such plans but for following quarters we always go through Ideas to see what customers suggest and put a lot of votes on.