If you need to rapidly switch back and forth between expansion / concealment of all notes in a large document, you can use an applescript like:
Code:
tell application id "com.omnigroup.OmniOutlinerPro3"
tell front document
set note display to in line
set refNoteRows to a reference to (rows where note is not "")
set blnExpanded to not (note expanded of first item of refNoteRows)
set note expanded of refNoteRows to blnExpanded
end tell
end tell
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