After a few days of fine-tuning, I've managed to write a program that successfully turns an abritrary uxntal program source file into the style that I normally use when coding. It should help me parse other people's programs more easily when using unfamiliar indentation.
All these experiments at structured editing, reassembly, auto-formatting are my poking at better understanding which patterns are used in a language that lacks syntactical constructs.
@neauoire so what did you use in the end? [4 or [ ( 4 )? I couldn't quickly understand it from the code.