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.
How is paying wind farms hundreds of millions of pounds to turn off wind generation not wasting money?
That's very different to wasting money in a way that actually uses up physical resources or people's time.