The jqxTree does not have such feature.
As you found in the mentioned forum topic.
But I would like to suggest you one workaround. You could transform the jqxTreeGrid looks as a jqxTree.
Please, take a look at this example: https://www.jseditor.io/?key=jqxtreegrid-with-one-column
After that, you could implement logic into it when starting to editing to appear textbox or some of the suggested widgets as in this demo.