I don’t think they should ever fill the seat. Permanently reduce the Court to 8 Justices. Going back to the original 6 would be even better.
No matter where you are on the political spectrum, I can point you to a 5 to 4 Supreme Court decision that you will say was a complete travesty. With only 8 Justices, every ruling requires at least a 5 to 3 majority. If the Court cannot get a 2 Justice consensus then they should send the case back to the courts of appeal and try again when they have a consensus.
If we thought Merrick wouldn’t destroy the Constitution, he would have been confirmed, wouldn’t he?