The generated numbers go to EDF and they pay me for FIT.
Which will continue unless you decide to change that arrangement.
Seems you have the answer.
Since FIT no longer an option with new solar installations, it is hard to get info on the old system. There are a lot of changes in how export is paid for newer installations, including the use of a battery.
The off-peak system does require a smart meter, but much depends on your average use, and size if any of the battery.
If I look at my own solar installation, I have 6kW of panels and 6.4 kWh storage, and I use between 10 and 14 kWh most days, as shown here.
This means I need around 6 kWh of solar production to be able to use off-peak and solar only, and not use the more expensive peak rate.
It is all well and good for me to say what the smart meter does for me, but that does not mean it will help for you. The off-peak only really helps me because of the battery. It helps more in the winter to summer, even with no solar at all, it means half my electric is at 8.5p and half at 30.17p so average around 20p/kWh.
But if I take what I produced with 6 kW of panels, then 3.5 kW would be around 7.5 kWh and without a battery only some of that will reduce the daytime use. I can use the off-peak in the day

this shows how I am storing off-peak to use latter, without that, I am not sure if off-peak will pay for its self?
It's worth being aware that moving from deemed export to metered export is a one way move - there's no going back.
This is my worry, for me, it was simple, I am far better off with a smart meter as without it no payment for export, but for you not so cut and dried. Some of the early FIT payments were silly, often they were paying more than they were charging.