Update xml-tuned files

Hi,

Since 2 years I always redo all my tuned xml files when an update comes and things break. I edit certain values in xml files using s4s (amazing program, thank you!). I was wondering if there is an easier way to update tuned files, or if my way is the only way. it becomes tedious to update all numbers by hand over and over, and it results in my mods taking quite a while to be updated. Am I missing something? I did see you can update CAS edited items easily, so I hope it's also possible for XML files.

Thanks in advance for answering my question!