Steve, I found a trick with the Code cell that results in a backdoor folding text result. If you have a Markdown cell (or create a new Code cell and assign to it the Markdown language type) then any line that begins with # can be folded. Code cells give line numbers to each line, and lines beginning with "#" characters have a little triangle next to the line number that folds the text in the lines following the "#" line. Like I say, it's a trick -- not a highly developed folding feature.

Bill: Since you have a direct line to Oliver ;) Here's a suggestion -- It would be really useful to be able to select several notes (contiguous or discontiguous) in the middle panel and have a composed preview of all those selected notes in the right panel. Some folks call this a "Scrivener view" after that feature in Scrivener.