Hi Chris,
You can set the docking style while docking using DockControl as follows:
this.dockingManager.DockControl(this.listBox1, this.listBox2,Syncfusion.Windows.Forms.Tools.DockingStyle.Right,200,true);
You can find more information in our UG at following location:
http://help.syncfusion.com/ug_81/WindowsFormsUI_Tools/default.htmlPlease let me know if you have any question.
Regards,
Dhivya.