Sentence length is clearly a good proxy for the harder to measure “length of independent clause with its subordinates.”
Although, I think it is helpful to bear in mind that punctuation marks at the end of a sentence are only a proxy for this, one can miss the forest for the trees.
Good write up!
My contrary opinion is that discussion about EU policy is frequently more ambitious than discussion about Dyson spheres. Improving policy is hard and unattractive, but really matters for the next century.