I see where you are coming from, but relying on something that actually is available for your installation (version) will be most predictable, documentation as it usually is on open-source projects sometimes lack constant updates.
Being said that as I noted the open source, everybody can freely make a pull request with changes they would like to see in it.
Link to documentation repository
AsgardCMS v2 uses Laravel-Menus same base as Pingpong with tests and multiple improvements.
Same concepts still apply, basically you would use same documentation but replace Pingpong with Nwidart so for Presenters base class it would be Nwidart\Menus\Presenters\Presenter.