Aeotec Energy Meter 2nd Edition 3clamp - Advice needed

I’m after some help from someone who has some experience with one of these. I won’t be installing it myself but before I involve a sparky I wondered if someone could tell me if I can use the equipment I have in the way that I want to?

I have an Aeotec Home Energy Meter (2nd Edition). Its 3 clamp 3 phase model (DSB28-ZWEU).

My home has a 3 phase supply. However, only one of the phases is connected to the meter and then onto the consumer units. The other two are not terminated and do not provide power to the house.

So, here’s the question. Can I use the meter to provide a whole house reading of the active phase using a single clamp or not?

I’m confused by a statementThe reason I ask is because of the statement on the Vesternet web site:
“3-clamp - ONLY works with a 3-phase supply, it CANNOT be used with a 1-phase supply”

If I can do that, could Ithen use the other two clamps to give specific reading for other items, for example:
The cable that runs to my workshop, or the cable that feeds my spa?

If you need more info let me know. Thanks in advance for any help you can provide.