I wish to do the same thing. If the software allows for multiple schedules, as
I expect, a second schedule could be set up to only enable the lights (also assuming that the program delay time allows for hours of zone enabled time). The rachio team would need to comment officially however I doubt that the box could drive the lighting directly, therefore you could add a relay switch enabled by the Iro. I plan on using this rely to turn on my 120 VAC transformer that drives the low voltage lighting,
