In the welcome beta email it briefly mentions about HW Priority dependent on your system set up but doesn't really expand on this

'And finally…. Stored hot water priority and a hot water heating state if you use a Sundial central heating valve.'

Could someone expand on this? As I believe i've got the correct set up (Zone valves, Boiler Relay etc) for this to work however it doesn't appear to be an option on my panel running the beta firmware.