Once  has be resolved and deployed the user manual tree should be auto-generated from the annotated values according to Template:User manual.
I did change the first view items, to show case how the hierarchy is build together with an arbitrary sort key per level to order (rank) those in a group by key and not by title.
If possible get rid of the docinfo template or somehow make it invisible as it distracts the reading flow. If we want to show version and document status, maybe using the page indicator is a better approach.
PS: I just got fed up with the navigation this morning while looking for some information!