Since the primary motivation for folding is to prevent visual information overload, I think there's not much value in expanding nodes, at same level, across _all trees _ in the entire file. (By the way, for the same reason, I'd choose to have all my files open by default with all nodes folded. ) So that's why I made the changes above to C3 and C4, to be able to fold/unfold all nodes _locally_, belonging to same parent node/subtree (As complement to fold/unfold at whole file level, and individual node level).
@intact , what did you have in mind with Fold Recursively, Unfold Recursively ?