Here's my start, after a couple rerolls and one resignation where a stupid early war screwed me up and cost the Great Library.
Looks decent enough, with nine resources after revealing one more gold in the fog. The variant rule restricted me from the very first turn: my only legal tile to work is the dyes, at 1-1-3. Fortunately the gold from that tile and a city-state greeting let me buy the wheat quickly.
I opened with a scout build, who got some fine luck from ruins. One popped 20 culture, accelerating me to the Liberty opener and worker policy quickly. Another popped Pottery after a few turns of research. Another upgraded my scout to an archer. Another gave Calendar!
So my build order was scout - granary (completed extremely early, on turn 15) - scout - monument - another worker to attend to the city created by the Liberty settler. Then the Great Library.
Besides the specialist science bonus, Korea's other ability is a "tech boost" each time a scientific building or wonder is completed in the capital. According to this thread, it's exactly as getting a Research Agreement, complete with the bonuses from Rationalism and Porcelain Tower. This bonus awards half the value of the median cost of all available techs.
So I set up the tech tree like this. Five techs are available, and the higher three are all the same cost, so that's the median. Now, the Great Library counts for Korea's ability, and so does the free library. So the GL gives two 50% tech boosts on top of its usual prize -- in all it slings TWO entire technologies for Korea! That's a no-brainer if ever I saw one. Korea's bonus resolves before the Great Library free tech, so I got Philosophy with the former and Theology with the GL itself, a major slingshot.
It's also said that both a real library and the GL free library count separately, so you can get even an extra research boost by building a regular library first. But that's not really worth it, turning 75 hammers into about 50 beakers.
One piece of micromanagement: Philosophy enables research agreements, but then sign any BEFORE you take the GL free tech. The cost of RAs goes up as you enter each new era, so sign them before actually taking the free tech into the medieval era. Only Wu Zetian here had the money to sign one with me. (Although this particular RA turned out as a dud, I didn't have the available techs manipulated well this time and only got half of Horseback Riding from it. Deep beelines tend to cut off availability of other expensive techs so the median cost becomes lower.)
Anyway, my slingshot prize was Theology, rather than Civil Service as the usual target. First, with variant rule forbidding the use of farmed regular tiles, Civil Service wasn't so hot anyway. Second, it didn't work out well to manipulate the median tech value while making CS available, which requires exposing The Wheel, so would probably require avoiding Mining in order to block the techs down on the bottom. Third, Hagia Sophia was a major target.
Here's an overview just as we completed the wonder. I expanded out to three cities. Busan is a quality site with two new luxuries and lots more resources, but honestly Jeonju was kind of a goof. I put it there because it had the 6-food river wheat and horses both in first ring for fast growth and happy (circus), but after that the city was pretty limited.
And why in the world am I researching Optics on a pangaea? Because it's the fastest way into the Renaissance. I've got a grand plan.
And here we are, the Renaissance reached in 225 BC. Note the culture counter, getting here just in time for a policy hitting. The whole point of this was to enable Rationalism and Freedom as fast as humanly possible.
To recap: I began with Liberty for the worker and settler as usual. Then the Tradition opener, which does make a big difference in border expansion, which my cities will need to reach all those third-ring resources. One more policy unavoidably came in that went into Republic. Then I reached the Renaissance as policy number six arrived. So now I was able to implement the overall strategic plan: get to Secularism for the +2 science per specialist, then go down the right side of Freedom for the other specialist enhancers.
Okay, so this report got away from the track of focusing on the specialist-efficiency idea. I've just been abusing Korea's research boost ability along with the usual technology slingshots. The cities aren't even working specialists yet, they haven't outgrown their regular resource tiles, and I'm stuck at a tight happy cap. But now we're about to start the main show.