Questions about Shelly Pro 3

The Shelly Pro 3 does not offer a specific function for displaying the energy consumption per output. However, it can be used as a switching actuator to control devices and monitor their operation. If you want to measure energy consumption, the Shelly Pro 3EM, which is specifically designed for energy measurement, might be a better choice. It provides a precise measurement of energy consumption data that you could use for your load management.

No, that probably happened due to an error during entry. Thank you for pointing this out. I have passed this on to the relevant department for correction and it will be dealt with as quickly as possible.

The switching inputs must be triggered with the phase of the Shelly itself. In other words, with what is connected to the "L" at the bottom. As you have correctly written, the inputs are independent of the outputs. Internally, the outputs are simply relays that connect Ix to Ox (x=1..3) when the output is set to "1".

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.