Ah, i never followed the thread apart from the first page, would have thought they correct stuff like that. However, i guess a definitely legit runner up is
DDRJake with his OTHER Three mountains by 1762 
Anyway, this was with Ryukyu, in an old version and he had severe overextension in the end, so its probably not exactly what OP has in mind.
@fastest occupation: Im not sure this would be much easier/faster, if you want to occupy large swaps of land over a large time your WE would got nuts because of call for peace. Keeping 200 provinces with 20 RR under controll without being able to give in to rebel demands sounds...hard.
20 revolt risk
-20% manpower recovery
+200% ship and army recruit time
-40% goods produced
+ 50% core creation cost (not relevant if you're just going for occupation)
-20% siege ability
That's pretty brutal. If you have the money to survive such a mammoth goods hit and the units you need already, the real barrier is that RR. 20 RR is massive, double what you get from 1.7 westernization. Can we overcome it?
Orthodox with 100 PA: +1 tolerance, -3 RR
Plutocratic: -2 RR
Humanist: -2 RR
Base tolerance: 3
Theocracy government tolerance: 2
3 stability: 3
tier 2 adm building: -1rr
Religious tolerance idea: 1
Oh, so we're spamming government buildings? We should take economic then. Some policies we can get from ideas so far:
Defensive-Economic: The Public Welfare Act: 1
Defensive-Religious: Edict of Expulsion: 1
Economic-Religious: The Moral Economy Act: 2
Maybe we want administrative also, which opens up
Administrative-Economic: The Judiciary Act: 1
Humanist-Administrative: Provincial Autonomy: 1
We're not actually coring anything, so a final push for massed occupation with these policies enabled isn't a big deal. If you tally this up, you get -24 revolt risk from either positive tolerance or -rr.
Assuming you had religious unity (and hell, you're a freaking Orthodox theocracy with religious ideas, you'd better), you wouldn't necessarily need 3 stability. Legitimacy is no concern for RR, because you're a theocracy. With religious/humanist, you could either make sure a culture is accepted or convert it before going for this push. You could also be the Papal State or even someone like Tibet, though the -rr margins are tighter.
Now, who can manage this? Papal states, Teutonic/Livonian, Knights, Tibet. I guess you could do someone like Novgorod too, but then keep RT at 100 and go full PA. You'd lose the theocracy +2 tolerance, but could still break 20 with no legitimacy to muck things up.
The best candidate is probably Lithuania that goes republic. Lithuania is a pretty strong start (stronger than Manchu, Ireland, or Japan) that can go Orthodox w/o too much hassle and has a -2rr NI, making it competitive with the Orthodox theocracy setup. To get the policies above, you need Religious, Administrative, Economic, and Humanist...lots of ADM ideas. You also need defensive and plutocratic, which is okay. 6 NIs total.