From what I can gather in the Rachio API documentation, there is a method for querying if the controller is currently running a cycle. In the present integration, there are controls, but no sensors for knowing when the controller is running a zone/schedule.
I would like to see sensors added to show if a zone or schedule is currently running.
The switches do exactly what you’re asking for. They show if a zone or schedule is running. I’m not sure what a sensor would show you that you don’t already get with the switch.