Its use is pretty obvious. It would really save idiots like me from losing half a day of work from accidental crashes because we forgot to save the TD project. Typing so much Python code in an external editor has lured me into a false sense of safety, that I did save, but in reality, I only saved the Python files, and not the actualy TD project.
Funny enough the whole UI of Touch is built in Touch, so yeah, thats always the question
Also have a look in the assets section of the website, someone already built one:
haha. I built one myself in like 5 mins, then added some functionalities as I went a long, such as resetting the timer when I press ctrl-s to save the file normally.