Include complete TOC in each volume of multi-volume works
In order to browse all the contents of a multi-volume work such as Encyclopedia of Christianity or Karl Barth's "Church Dogmatics" and navigate to another part of the work when you don't know where you're going, you have to open each volume and poke around in each one's TOC pane.
The TOC pane should show a global table of contents covering the entire work with all its volumes. It seems this should be technically feasible since it is possible to navigate directly to a different volume (within the same tab) if you know what to type into the reference box. The problem is, without knowing the contents of the work intimately, you can't do this.
So please make the TOC panes cover the entire work for multi-volume works!