> I should add, for context, that my friend and I are talking about writing beautiful essays here. If you want to write the most precise thing possible, you need to edit mercilessly and accept that the writing ends up flat and disjointed.
I don't think that merciless editing and beauty are opposed. The author perhaps underestimates the extent to which artists mercilessly edit their own work. The author employs the metaphor of musical improvisation, but the best musical pieces are usually composed, not improvised. I like jazz, but... not for the songwriting. For stream of consciousness writing, you'd almost be better off posting on social media.
I've been blogging for over 15 years, and my advice, admittedly ironic, is to not take advice from anyone. Actually, that's my advice on many subjects. Everyone wants to impose their own little idiosyncrasies on you, but what works for them won't necessarily work for you. One's idiosyncrasies are not universal truths.