So the last 10 years in game time some good progress has been made. It is now 1641 and I'm now up to 213 provinces (including 5 colonies, 2 of which seized from Russia). My vassals and PUs I think give me another 87 provinces or so. So another 200 provinces to acquire in 180 years, which seems possible, but my other worry is that I need to starting integrating vassals faster because of the -30 penalty. It does reset after 20 years which is good, but still it means I need to integrate 2 vassals every 30 years, and... well, there are only 180 years left. Spreading Sunni is very fast, and with Defender of Faith that's 4 missionaries which is plenty. So my bottleneck is still OE.
Vassal + PU province count: Zhou 5, Xi 17 (Sunni), Shun 21 (Sunni), Persia 13, Nogai 14 (PU), Mewar 10, Morocco 1, Giowalior 2, Khrosan 2, Bengal 2, Ryazan 1. 11/8 Dip Relations. Bengal has another 5 or so cores, Khrosan also 5 or so, Ryazan who knows how many provinces they'll be willing to buy.
I think vassal feeding is still kind of viable. Milatarist rulers buy most things, I think even different culture (but perhaps only same culture group?). Admin and Diplo rulers don't like to buy anything. Balanced rulers, well, they are in between. So you need to be kind of lucky there.
OE at 164 right now. Siberia is pretty much done colonizing, maybe 2 empty incognito ones left, ones that Russia no longer has access to. Cape is at 955 inhabitants so I'll need to start expanding there, or maybe take Taiwan first. I don't have the explore idea, so I can't get to Oceania, whose 20 or so non-arid provinces would help a great deal. Yeah, Exploration is more important than I thought.
One thing I realized is that I think same culture group reduces coring time. So hopefully the 30 or Ottoman Turkish provinces shouldn't take too long to core (though still quite expensive). Unfortunately I think all the minor nation cores have expired. Coring time for someone else's provinces with claim and reduction is now pretty much at 10 years, probably will only get longer.
Turns out the war against Russia wasn't too difficult. They annoyingly are now protectorates of Oirat, Kazan and Golden Horde which are full of low-value provinces that I love. Earlier they actually invaded Crimea, which is a protectorate of Ottoman, and those two guys just cancelled out a slew of manpower. After that Russia was not difficult. Westernized units trump the Eastern units, especially when they take so much attrition. Their eastern Siberian provinces are so cheap war-score wise.
Next up: integrate Zhou and Mewar, DoW on Ottoman or Tunisia (to feed Morocco). DoW Timurids (30 regiments more than enough) for both provinces and Khorosan feeding, DoW Assam (or is it Shan) to feed Bengal. Great thing is that by now Xi does all the fighting for me when it's in Southeast Asia. Actually, I forgot to DoW vassalize Byzantium (released in a previous war), I was wondering if they'll buy lots of Greek provinces. But Ottoman took their Greek one and they're left with only Cyprus now.
So I think not cutting off Russia at Siberian chokepoints is a perfectly viable strategy. Much more work, but a lot more action :happy: