Surely they could ahve got around the password isseu with a powerline connector cabled from the router and directly read by the meter - no need for a password since efectively a direct link? or would it cause problems with neighbouring systems on the same phase?
I suffer from 'ruralism' too
There's lots of inventive ways that someone could choose to use now, but perhaps worth remembering that smart meters are pretty ancient, and the spec was set in the early 2000's. In some ways, by the time they are rolled out fully there won't be a need for them any more, as they came about as fix for a grid stability problem that was foreseen decades ago, largely caused by the predicted switch away from high inertia, predictable forms of electricity generation to low inertia, relatively unpredictable, renewable generation.
Back then, all the predictions indicated that the grid could have a significant frequency stability problem, as a consequence of renewable generation not being sufficiently controllable to allow for normal variations in demand. In the worst case, it was predicted that we could get outages so severe, due to the need to close generators to protect them when the frequency dips too low, that the grid might have to black start. This has never truly happened in the UK, closest we ever got was the grid division that occurred during the 1987 storm, that split the grid into two, as major disconnects operated to protect the network. It took a lot of work to resync the two halves of the grid, in order to allow the disconnects to be reset, and was a bit of a wake up call as to just how challenging a black start might be.
Lots of lessons were learned, and one of them was that there was a need for more load shedding capability, the second being that there was a need to be able to very accurately control loads during any resynchronisation process. Industrial/commercial supplies already have set load shedding, priority tariff, arrangements, so that the DNOs can turn off supplies to the lowest priority customers if there is a frequency dip event, turning off more customers going up the priority list if need be, in order to match demand to available generation/distribution capacity. It was decided that there needed to be a way to turn off domestic consumers as well, in order to give even greater load shedding capacity, but more importantly, to allow loads to be switched back in very gradually, during a black start recovery.
This is where smart meters came in, as they were originally designed just as a way to be able to selectively turn off and on loads remotely. If there was a serious frequency dip event, then the DNOs could load shed by turning off both low priority industrial/commercial consumers, and also domestic consumers as well. The idea was that this would give them a greater range of control in an emergency, and so help prevent the sort of cascade failure that could otherwise happen (and which nearly happened in August 2019 with the Hornsea/Little Barford incident).
As the spec for smart metering matured, there was a realisation that convincing consumers to have a remotely controlled power disconnect device fitted might be an uphill struggle, but that offering the ability to have access to variable TOU tariffs might be seen as attractive. As a consequence, smart meters are "sold" on this basis, and the fact that they all include an internal contactor to remotely disconnect supplies isn't widely advertised. There was also a hope that, by encouraging widespread use of TOU tariffs, the risk of there being a major low frequency event would be reduced, by reducing peak demand.
Since then, things have been changing rapidly, though. The idea of large scale battery storage, for example, that could behave much like spinning reserve, and add a lot of inertia (and hence frequency stability) to the grid wasn't even dreamed of. Nor was the fact that such battery storage could be co-located with wind and solar generation, such that it can reduce some of the supply variability. If I had to make a prediction, then I'd suggest that smart meters won't be needed, and won't offer any significant consumer benefit, in around 10 years time. By that time I suspect the degree of peak to off-peak variability we have at the moment will be a thing of the past, so there won't be any incentive for domestic consumers to benefit by shifting demand.
