I had E-On smart metering (gas and electric) installed in 2011. This apparently worked (just) over a SIM card to an O2 connection that was read monthly.
When I swapped to First Utility in 2014 I was told they could not read the E-On meters! Still the internal display allows me to read my meters without going outside each month!
I all of the papers relating to mass install of SM there is no mention of the Data load that this would require, even greater when they switch to the Half Hour Settlement! For the normal domestic user having about 3 or 4 heavy load devices (cooker, washer, dryer, heating) the idea that we might be cajoled into altering our use pattern by small differences in tarrifs is straight out of cloud cukoo land! Cook a meal later? Perhaps do the washing later at 2.00am in a badly insulated Flat? so you ake up at 7.00 am with a load of wet washing?
as to allowing utils to turn me off? No- way -Jose!!