I have 6 x Quattro units in a 3-phase configuration. If I want to use the K1/K2 relays and Aux inputs can I use them on any unit - do they all behave the same way? I would assume that since the same configuration is loaded in each unit they would all be active?
Each relay can be used for an individual function and can be programmed individually.
When programming the system, first sent the configuration to all units. Then afterwards go into the settings of each individual unit. Do this via “VE.Bus system configurator” and select the phase and then right click the Multi to go to its individual VE.Configure so each relay can be individually configured.
See this screenshot: 
