I have a large lot and 24 irrigation zones. The 16 zone unit is not enough. Wouldn’t it be a simple change to increase the number of zones? Better yet make the zones modular so you could add zones in the same box as needed; that way you don’t need to have multiple units.
Can 2 zones be run on the same line by the way; not that you’d want to but if you had to?
Is there an irrigation master pump capability? this may be the master valve feature. Can all the zones be programmed to use or not use the master valve/pump?
Can all the zones be programmed to use or not use the weather based data, just straight timer? i.e. under eaves or enclosures - no rain
Are there multiple programs i.e. A, B, C D available?
Say you had a drip system with low volume flow, why not be able to run 2 valves at the same time, make this a feature in Program D for example.