Probably the cheapest and best option is to build more wind and not care too much if it increases curtailment.
Yes, all the things mentioned should be looked into and done when it makes financial sense but "wasting wind" is much less a thing to worry about than "burning gas", and I'd rather waste wind than waste money.
Maybe not: "The Transport Secretary announced on 19 October 2022 that the Transport Bill which would have set up GBR would not go ahead in the current parliamentary session."
the franchising sysem won't be coming back
[0] - interestingly his "RailNatter" this Wednesday was titled "How to fix Britain's broken railways". I haven't watched it yet, but it will certainly feature some good insight: https://www.youtube.com/watch?v=CmKhVjw1xDA