You can rename a user input, which makes a file saved in an old version unaware of that the old user input value is the value of the new input. Nothing actually breaks, but the input gets its default value, so you should handle migration. The situation can be worse for API migration because a model file for Java® cannot execute if you try to access the old input.

The Settings window has the following sections:

In the Old name label you see the old name, and you can adjust the new name in the New name field. The automatic logging of changes should prepare new Rename User Input nodes with the a correct new type.

Identical to the Compatibility section of the Change Type node.