I use dual portrait monitors to look at 2 PDFs at the same time (usually a copy of a tax return on one screen and source documents on the other). The bookmarks are very important to me, but when the bookmark pane is on the left, it makes the PDF itself too small and defeats the purpose of using portrait monitors. However, if I could put the navigation pane at the top (below the tool bar) and display the bookmarks at the top of my screen, that would be very helpful. I looked all over but couldn't find this as an option.