Much of this seems to be US-Centric, with talk of HVAC and the like.
In the UK, Smart Meters are dumb meters that can be read, and turned off remotely. Typically they only talk to the remote display that tells you exactly how far you have to bend over because you've had the central heating on for 12 minutes. (Although to be fair, most seem to have Zigbee so COULD talk to other IoT devices, if you had them, and they were in pairing mode)
The connection to your consumer unit / fuse box is via twin and earth, and the consumer unit is just a bank of switches. No smart stuff there. Controlling your smart meter remotely cannot turn on and off individual circuits, it can only turn on and off the thing as a whole.
In addition, you've got a fuse - somewhere between 60A and 100A - protecting your house. It's the box with the serial number tag on. If someone really wanted to mess around with your stuff, and even if they found a way to flip the whole thing on and off to try and cause an "explosion" (I think they mean fire, but explosion sounds better) then the fuse would pop way before enough current was drawn to make your wires "explode". And then each circuit is protected by some sort of overcurrent device, so you can't even try to feed all 100A to the kettle to make that pop. The 20A breaker on that circuit would trip first.
In short, someone has been watching too many films.
Biting the hand that feeds IT
