I'm trying to create a left sidebar vertical menu block, that will open up to display 2nd-level menu items on a hover or click. The dropdown style does that, but displays the menu items with "nowrap" by default, which is problematic for sidebars (it doesn't increase the container width, it just runs over the right edge). The hierarchical tree style is confusing, it says "Blocks that start with the 2nd level or deeper will only be visible when the trail to the active menu item passes though the block’s starting level." but in fact displays all menu items up to the Maximum depth, always.
Is this something I need Nice Menus or some such to do? It seems like a pretty normal navigation style. Maybe it's outdated?