In the old UI, switching between Rachio controllers used to be simple. Select the controller at the top of the screen (mobile or Web), and you'd get a drop down showing all the controllers for your account and you could simply select the one you wanted.
In the latest version, it's now become a multi-step process which is not at all obvious.
One of the real strengths of Rachio is its user-friendly UI. Having multiple controllers isn't that big a deal when it's easy to switch between them, but now it's become a real pain. Please put back an easy switch option.