@Chersfrozenface - this is unlikely to happen. The UK Government will fight it on the basis of the legislation now and its power. To start revising the legislation in the Equality Act as the litigation is on going would perhaps mean half admitting the issue or conceding part of the self ID case is valid. It doesn't have to do that. It could instead spoil any case by Scot Gov by announcing policy moves or prospective policy moves during the case's progress and give comments by Badenoch and the current gossip about Sunak (very socially conservative) then I think this is more likely.
You would have to say something like... "The UK Government refutes the Scottish Government's claim... on the basis of the current legislation as it stands. The UK Government is considering changes to the scope of the legislation".
This might warn the Court of Session off because it would be clear that their ruling could become academic quickly or that this is a political issue where they should not interfere or they make a very short judgment which declares in effect that the UK Gov has the power to do this and it is valid.