yep, NC first and HG + Petra right after. used the techboost from NC to get masonry for marble iirc. didnt try for GL as it is nearly impossible to get on deity. cant remember if i built or rushbought the library though.
thats right, the bpt on the screenshot is mainly the result of the freedom finisher, which doubles the yield on academies (then 20 science for Korea) and also on the landmarks i settled with great artists (4 science with Korean UA). i also settled next to a mountain and thus had access to an observatory (extra +50% science) and focused on population growth whenever i wasnt building anything crucial in the city. because i also had a relatively large culture and gold output in that game, i was able to take the policy in the Patronage tree that gives science from allied city states and (at least in the late game) ally all of them that were not puppeted by the AI players. this accounted for about 200 bpt i think.
the bpt at the time of the screenshot are actually even lower than they were before (i dont remember exactly, but peak bpt was higher than 1300) because i had already finished all the spaceship techs and focused on production, e.g. didnt run any scientist specialists (and probably no merchants and artists) anymore.
that is very impressive mate. trying your save now for, i think, 8th time. did very poorly. at last managed to get HG+Petra (went straight to maths), but realized, that can't get education ->astronomy-> renaissance early enough, only at around turn 120 or so. i'll try to get NC first.
could you remember at around what turn you get HG and Petra?