It would be useful if the expansion state of menu items persisted between sessions. For developers this is just an annoyance, but for editors it can be quite confusing as they’re already trying to get their heads around the data model, and having to open everything up every time they come back to it doesn’t help.
I would actually go further, and suggest that the menu should be expanded by default (at least to one level deep). A well-structured menu is a key part of whether clients/editors are able to understand the CMS or whether the whole thing remains a mystery to them.
