You can manipulate the layout of some Diagrams in the µRadiant.
You can group DataElements by adding them in similar packages.
packages diagram draws the different packages as separate rectangles.
This can be useful to define subdomains in your Components around coherent features.
You can also add options to the model to give hints to the layout algorithm. Keep in mind that the algorithm will try its best to follow these hints, but can't always give a perfect solution.
Hiding unimportant links generally yields the best results to create a clear layout. Options for links should be placed on the Field.
mr.diagrams.top: Forces this DataElement to appear above the DataElements it is linked to.
mr.diagrams.direction: Forces a link to point in the defined direction can have
mr.diagrams.length: Forces a link to have a certain length. Use an integer as value.
mr.diagrams.hide: Hides a link or DataElement from the Diagram.