If you expand a tree node with 1000 items in it, and that tree has an ng-template the performance is very poor. It takes 7 seconds on my machine, see here https://www.telerik.com/forums/slow-treeview-with-large-datasets Please add virtualisation to the TreeView so that not so many DOM elements (and therefore ng-templates) need to be created.
When using the "checkBy" attribute to configure the data field for the key definition, then the indeterminate state of parent nodes is broken.
To reproduce the issue have a look to this StackBlitz: https://stackblitz.com/edit/angular-okpokx
There is a filternodes option available but not with checkboxes. Would be glad to have Treeview filter(with checkboxes) something similar kenod jquery component(attached the link and screenshot for your reference). Is there any plans to release this feature in near future?