IMO the only valid move for Biden right now asap, is to use his new immunity powers to invalidate his immunity powers, as a display of self checkmate.
Declare the full supreme court under threat of death has to go back and redo the decision, and all of them must vote to reverse it and remove the presidential immunity, or be hung.
This of course means “if you dont remove my ability to kill you, you will die”.
Its the ultimate display of being handed ultimate power, and rejecting it through the power itself.
I cant think of any other move that makes sense really. It would be a headache in court but thats what the supreme justices get for making such a stupid ass decision.