What problem does this address?

In the current Menus screen it's possible to add multiple entities at once pretty quickly (eg: Pages).

In the new Navigation Editor screen doing this is somewhat laborious and cumbersome involving repeated clicks and waiting for the link suggestions to pop up. Moreover, you can't immediately see all the entities available to you in a single view (basically we're missing the View all option from the existing screen).

I see this type of bulk creation interaction as being fairly important for folks who know how they want their menu to look and want to built it out quickly. Having to jump through the current interface's hoops seems over the top for them.

What is your proposed solution?

It should be possible to bulk add entities of any type. This will probably require some upfront UX and Design thought. One idea is to do this via a Modal. We'd need to consider how we'd handle nested contexts.