There are two much simpler things government can do now. The first is to push those legacy renewables onto CfDs. Why would they give up their nice rents? 1. lots are coming to an end - a long term stable income is attractive. 2. Reform has promised to cancel legacy renewables, and it can easily. A CfD is harder to rip up as it's protected by private law - but as we've seen with Trump the law is not always a barrier to ideology. 3. A bit of stick. Government brought in the energy generator levy post Ukraine to address windfall profits to electricity generators. I wouldn't be afraid to ramp this up as an incentive to change (or fail safe if they don't move).
On those short term actions, I liked Sam’s take on how you could push older renewables (which make a lot of money, especially when gas is expensive) on to CfDs…