Because the cutscenes operate on active actions blocking the execution, dialog items can be waited on, even multiple at the same time while complex action sequences happen on the background.
Cutscene sequencing tool for Unity, that is not time-bound
Cutscenes are constructed of action sets that can be either 1 frame or longer. When the system hits the last active frame of an action that is yet to finish, it will wait for it to finish.
A getting started tutorial for cutscene with navigation.
Because the cutscenes operate on active actions blocking the execution, dialog items can be waited on, even multiple at the same time while complex action sequences happen on the background.
Cutscenes can have navigation that needs to complete before proceeding. Alternatively the navigation (and all other actions) can be skipped to the end if other actions finish first.
Here is an example of navigation path preview being rendered in the scene view. Note that since the position of the navigation agent is not deterministic, the path is not necessarily final.
Extras package contains additional scripts that couldn't be included in the main package. These are showcases, not necessarily production ready at all. You may or may not have use for them.