Depending on which firmware you are using, earlier firmwares have a ‘sequential’ flag per zone. By removing the ‘sequential’ flag you can have the zone run with other zones in parallel. The current firmware has a ‘sequential group’ feature which is more flexible. You can put zones into different sequential groups. Zones in the same sequential group are serialized and run one after another; zones in different groups can run in parallel.
A lot of customers have a huge variety of different features they want. It’s literally impossible to have one firmware that fits everyone’s need. In the worst case, you can set every zone into ‘parallel’ group and create multiple programs to manage the zone running patterns manually.
Also, I’ve seen quite a few customers who want to run more than 10 zones at the same time. I would absolutely NOT recommend doing this. The controller is NOT designed to run a lot of zones in parallel. It’s not a software issue, it’s more of a hardware limitation. The power adapter needs to withstand a huge amount of impulse current to open that many zones simultaneously. Also, the circuit cannot withstand that much current either. So while I understand there is such need, I wouldn’t go crazy on having too many zones open at the same time. If you really need to do that, you should use an external relay, which can withstand a huge amount of current.