Seems like a nice application for OS. I’d be interested to know what you see as the key features from a central control/monitoring perspective and if you find ways to know when something is wrong, without visual inspection.
The model I have for integration with automation systems (in this case Crestron) is to provide simple controls (enable/disable, manual run, etc.), quick visual monitoring (zone/program activity), and notifications, particularly when something is wrong. I let OS and the supplied Web UI and Mobile App do what they do best: configure, program, schedule. Of course, you can still use the supplied tools for any purpose.
Determining when something is wrong is the most difficult. Having to regularly monitor the OS log or noticing that plants are drying out are not the best ways find to find out. People want automatic weather based adjustment and everything to just work as they expect, but in the case of some failure they want to be notified of a problem before they incur landscaping damage and cost.
Personally I don’t use the auto adjustments because I don’t think they reliable enough yet (not just with OS) and I don’t have good enough ways to spot problems ahead of time. Knowing that server calls are not working is a simple check but knowing over time if the weather based adjustments are correct and if they are what you need across your various irrigation zones is a bit harder.