Length Reduction option for yEd doesn't exist.
In our CIF to yEd transformation we mention that:
Good results for model diagrams can often be obtained by using the Orthogonal layout. Select Layout Orthogonal Classic to show the 'Orthogonal Layout' window. Click the Dock button to dock the window. Once docked, select Integrated for Edge Labeling and Free for Edge Label Model. Also enable the Length Reduction and Consider Node Labels options. Press the Apply changes button (the green rectangle) at the top of the docked window to apply the changes to the layout.
In my yEd Version (3.21.1) the Length Reduction
option doesn't exist, see below: