The second most recent one is The Thief Knot, which is a spinoff about Marzana from Ghosts of Greenglass. It's really fun in that satisfying way books are when the characters can work together to solve a mystery really well.
She calls it the Roaming World, because the one big thing that shows up in every single book is the roamers, in one way or another, though the books that happen in Nagspeake don't really center around them as much. Also because you're right, milford-verse would be awkward.