Front pressure storage

After the TÜV criticized the brake lines at the rear, I wanted to replace them.
But at the exact look it are the lines of the decommissioned level regulation! Everything's still in there, up to the pressure stores. The pressure stores were sealed on the exit line to the spring leg.
Now I want to remove the cables and convert them to normal brake force controls on the rear axle.
My question:
Do I also need another pressurized memory in front or can I just seal the connection to the pressurised memory?