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.
Despite the insistence that Closed Cycle Gas Turbines can't react quickly, because they're by far the largest component that we could start and stop the UK does in fact very quickly increase and decrease output from the CCGTs. For example this morning 2.79GW at 0600 to 3.89 at 0700.
There are much faster options, batteries, import, even the pumped storage is seconds instead of minutes - if available, but CCGT is just not that slow to change compared to the weather. In that same period the wind power went from 10.9GW to 11.4GW. 500MW is a lot of power but it's not more than 1.1GW