The problem is that doing any of these things in a matter which will stick will require amendments, because that is the only process that this compromised Supreme Court might respect. (And even that is not a given: I wouldn’t put it past them to say that any amendment not passed by a Founding Father is invalid, or something).
So the first thing that needs to be done is to “pack” the court. (I prefer the term “unfuck”, but that is less PC). This can only be done if Democrats take the Presidency and both houses of Congres, and nuke the filibuster. But it’s that important. Dial the fucker up to 13, then go to Republicans and say “OK, now we need to work to fix the courts together. You can decline, but if you do you will watch Momala appoint 4 additional justices under the old rules, to lifetime terms, and bank on getting your own trifecta to re-fuck the Court”.
While we have the amendment process open, we also need to set a limit to how long Congress can deliberate on any appointment, not just SC. Once a President makes an appointment, the Senate shouldn’t be able to sit on it indefinitely. It should be guaranteed to get a vote in the full Senate within X legislative days. The Senate can vote it down, of course, but then the President can nominate someone else. Republican Senators challenged Obama to make a centrist pick for the SC, and he did. Mitch and Lindsey sat on it for months because they knew that it would pass if it went to the full Senate. This process basically gives the Senate Leader a veto over both the President and the will of the overall Senate, and cannot be what the Founders intended.