You can connect the menu items to microflows, and create deeplinks to those microflows as well. Thats quite simple to achieve.
Setting up the links should be easy enough, if you just create a Navigation entity and create an object for each Navigation item. From there the Deeplinking module can pass them to a microflow. The problem there is opening a different form for each object. You could maybe store the form name in the object and open in with a Java action:
You can probably handle subitems using a self-reference.