I was just thinking that. I just need a willing volunteer or myself. You probably know this, but basically what happens on an install is we put in the meters then call hq with the following info:
Comms hub serial number - the bit they talk to.
MPAN and MPRN - the ref numbers of the property.
Gas, Electric and IHD (in home display) serial numbers.
They then communicate with the electric meter, that then prompts us to turn on the ihd and it pairs, then the same with the gas meter. It would be worth trying with a third party CAD as I suspect they only want to know the serial number to confirm its the right one and not an attacker. Though I’ll admit I don’t know exactly how the ZigBee Han is implemented. The people at hq might notice that the serial number is vastly different to any of the two models we use. Also, we tend to use two different smets 1 meter sets. The displays are parable with both though there was one batch of chameleon displays that only worked with one manufacturer.