This is a very nice addition Kris! 
Since we’re about to introduce a new homepage via the custom-homepage outlet, I’m curious if this new setting will include the custom homepage when a plugin or a theme-component introduces one. As I was planning to update user preferences to reset the homepage setting to default -1.
So, following up on that will this new setting update the options in user preferences’ homepage setting as well?
Lastly, if default homepage is set to first item in top menu, and there is a custom link added via api.addNavigationBarItem() and placed as the first item, will it actually be treated as the first item?