Then maybe we aren't talking about the same thing. When I added an employee in Washington, I had to apply online and then call them directly to get the employee set up. One of the things I had to do was buy Worker's Comp insurance through the State of Washington, because no one else will sell it. Also, I had to get my UBI number from them.
Ideally I would tell you guys "I have a new employee in Washington!" and that would be the end of the story, you'd do all the rest. That's what I'm hoping you can get to at least!
(To be clear, the part you can do today is already amazing and super helpful, I'm just being greedy because I'd rather spend time on product than on calling the State of Washington