Welcome back!
I can’t definitively answer some of your questions, I’ll leave that to others who are more knowledgeable.
Maybe @beaylott can help?
There’s a very long topic he started here, which might help you: A taste of things to come? - UK smart meter data access
In theory, the meter would be capable of that, but from comments made here, it appears not. It seems most UK smart meters closely emulate the earlier electronic or even the electro-mechanical ones.
I believe that’s correct - because there won’t be a “no-power” always available output from the gas meter, which must rely on an internal battery to send its data to the electricity meter, which acts as your base station. You could ask a competent installer to supply and fit your own meter (having a suitable pulse output) downstream of the “not-so-smart” meter provided by your supplier.