Changing the script editors text without modifying the undo-redo?

I posted this question on the godot forum, but that has been overrun by bots like crazy, it's all random characters, so probably some AI.

I want to edit the text of the current script editor without modifying the internal undo-redo of the editor.

So essentially I want this to be possible:

1. User writes some code
2. Program modifies it, maybe imroving the formatting and such...
3. Program then reverts to previously written code
4. User is able to undo their last code addition, without the programmatically inserted stuff to show up as the last undo-step.