Thanks for this post, it's very informative!
One thing I don't get is that in one of the other posts you mention that ULPNode wakes up every 30 seconds and in this post you say that it wakes up every 100 seconds. Is 100 seconds sleeping time just for prototyping purposes? I'd imagine that you can change that time by changing the value of a capacitor and for a final version you would use a capacitor that will discharge in 30 seconds. Is that correct?