At this moment, we can decide if we want to show the table of contents, or not. This means that I can have my custom navigation, or the World Anvil standard navigation.
To show the standard navigation within the world sidebar, I need to activate it for my world front page, too. This may be something you don't want to do.
My feature request means, that we'll get a second option within the world config. This would allow us to activate the standard navigation for the world sidebar, without having to activate it for the standard front page.
Sadly, this is a very specific request. I can't think of another use, than the one described. Sorry :/
I use the BBCode in my sidebar navigation, so I can custom order everything. Not sure if that may be of use to you?