[tech sidebar] fwiw, I only get that effect when the window is not maximised - something about the framing of that page seems to scramble if I have say a half-screen window. [/tech sidebar]

I don't fully share your doubts, Capfka - once the full power of modern computing gets trained on the tree logic as a corpora, I suspect a good approximation may start to emerge. But you're right of course - that which humans process without much conscious effort sets a fiendish task to analyse and an even harder challenge to replicate...