I run Home Assistant at home, and want to properly integrate my hot water heating, ideally also with HWC energy monitoring.

I have two electric hot water cylinders, one 3kW, and one 2kW. Each is on its own 16A breaker. I want to have independent control of each unit through HA so I can set custom heating schedules, boost when I need it, etc, and know how much power they are using.

I’d like to mount the gear on the DIN rails in my switchboard (by electrician).

What hardware is recommended here?

A Shelly Pro 4 PM looks like it can handle the switching without needing a contactor, and it will also give me power monitoring of the loads, plus an extra 2 channels for ‘other stuff’ later on. Potentially an issue that it recommends only 10A per channel even though it’s rated for 16A.
https://www.lykalyte.co.nz/products/shelly-pro-4pm

I assume an alternative of 2 x Shelly Pro PM would also do the trick. These appear to be able to do 16A each no issues.
https://www.lykalyte.co.nz/products/shelly-pro-1pm



Or another alternative, the Shelly Pro 2PM?
https://www.smarthome.com.au/product/shelly-pro-2pm-double-relay/

Can someone please confirm (or not) that I’m thinking along the correct lines here? Am I fine without using a separate contactor, particularly for the larger load?