Hi Jeff,
Thanks for your interest in Syncfusion.
If your intention is to make the Symbol nodes to remain selected ideally, then you can implement this by adding the nodes to the Controller.Selectionlist NodeCollection.
I have created a small sample exhibiting this behavior, Kindly refer the Sample and the ImageFiles.
Please let me know if you have any further queries regarding this.
Also please specify where the nodes need to be added to the selection list. I am referring the ChildrenChangeComplete event method.
Regards,
Praveena.
SymbolSelection.zip