There is no Rogowski coil support in IoTaWatt. Are you saying that the incoming mains are 9 cables “as big as my wrist” or three bundles of cables “as big as my wrist”. My wrist s 60mm at its widest point, so a 1600A x 80mm would work if it’s the later. I have another request outstanding for that special order CT, so will probably be ordering soon. I expect they will be about $150 each with 3-4 week lead time.
The available unit is an ESP8266 and can be queried at 5 second intervals for the latest data.
From what you are saying about a 2000A service, it seems more likely that learning what the usage patterns are could result in significant equipment and usage changes than switching off a few appliances at high demand. Also, with such a large service, doesn’t your tariff include charges for VAR?