Currently this could be accomplished through methods.
Expose a BringIntoView or ScrollIntoView method that would scroll the TreeView to a specified TreeViewItem. Available in R3 2018 release. For more details on the feature refer to: https://docs.telerik.com/devtools/xamarin/controls/treeview/treeview-scrolling
Provide an option to allow the checkbox to be rendered to the right of the node's content.
A mock code example:
<RadTreeView CheckBoxHorizontalOptions="End" />
Please let us know: