Can you monitor the reactive power in the local grid at your own house connection?

Or would one also have to measure/know the currents at the network operator’s transformer? Someone mentioned that the so-called "phase position" means something. That is, that they don't have 120°, but something else… Or what does "phase position" mean?

Does it help the power grid if a consumer places equal load on all phases?

Here, someone describes an inverter that ensures that all three three-phase phases of his house connection carry the same current. He did this by feeding more power into phase 1 when the washing machine on phase 1 was heating up… Or does an "unbalanced load" balance itself out due to the large number of consumers?…