Hi,
Currently there is no direct way in DockingManager to do this, But you can able to accomplish this by retrieving DocumentContainer object from DockingManager using VisualUtils.FindDescendant() and set its AddTabDocumentAtLast = true before adding the children’s to Children collection of DockingManager , Please find the sample the attached sample for more idea.
Please let us know if you have any queries,
Thanks,
HemanthKumar K
AddItem_ecf8553a.zip