Question about Shelly Pro 3

Exactly what I do with it: switch a 400V three-phase hot water boiler heating rod. But: I haven't found a way to switch all three relays simultaneously via the native Shelly app, which could be important with regard to the star point. However, this is possible via the API: If you use Home Assistant, you can create an automation with actions executed in parallel. And: If you haven't already done so and if possible, put the boiler heating element on a separate fuse.