One issue that has seemed to pop up recently is how do you change the offset distance of planes in different configurations? There is a very simple way to do it. Right click the offset dimension of the plane and select Configure Dimension.
Once you select configure dimension, you will see a Modify Configuration dialog box. The great thing about this command is if your configurations are already created they will show up in this box and all you have to do is change the dimension value. If you have not created the configurations yet, you will then be able to add the configurations you want by simply filling out the Create a new configuration field.
SOLIDWORKS also allows you to create a table for your new configurations so editing the dimensions is extremely easy and user friendly. All you have to do is fill out the table name and select Save Table View. Then you can open the table from the Configuration Manager.