If a CM is opened as a nested one and is defined above its parent then that CM sort of hides behined the parental one. Hence the need in properly set z-index property.
Currently nothing stops users from passing the disabled prop to <cm-item> component. But in such a case the item's action would anyway be performed. Need to be fixed.
Maybe it might be a good idea to give users the capability to navigate through Context Menus using the keyboard. For example to be able to select the next item with [arrow down] key, select items with [enter] and open nested Context Menus with [enter] or [arrow right] and so on.