I am sure there are many people who have a need to control zones in two or more distributed areas around the house.
So basically if you have front yard and backyard, you would need independent controllers which can be costly and hard to configure/control.
I have designed and implemented RF bridge that would extend zones control outputs to the remote sprinklers (up to 100 m). Its completely hardware and totally transparent, so Rachio will not even know that sprinklers are located at the remote location. The bridge consists of two small modules ( based on the number of zones you need to control it can vary from 1 - 4, or even 8 ) - one locally connected to the Zones output ( no additional power is required) and another at the remote location where your sprinklers wire are located ( will require AC so 24V control voltage can be generated)
Works very reliably and can be inexpensive addition to your smart sprinklers setup so single controller can be used to control multiple distributed zones.
If anyone interested in more detail please get in touch : bingoeugene at gmail