The Freedom to Vote Act is more necessary. The Constitution grants Congress plenary authority over House elections and near plenary authority over Senate elections if it chooses to exercise such power. That alone would be a significant step in the right direction. The independent state legislature theory would have no legs if Congress chose to act. Chief Justice Roberts in his majority opinion in Rucho v. Common Cause specifically mentioned the Elections Clause as a way to do something about gerrymandering. There's also nothing stopping Congress itself from drawing the maps for each and every state.
This will be a horrible precedent. Consider the next R trifecta pass a law to give all congressional map drawing power to itself, and gerrymander the House so that D can never take it back.
