It's getting harder to deal with remaining infidels. Initially my vassals aligned themselves into alliances by religion, so when I fought 10 of them, that meant 10 conversions. Now it's all much more mixed, so 10 rebellious vassals might mean 2 convertible infidels, 2 too big infidels, and 6 others caught in the conflict.
Fortunately I have another tool at my disposal - enforcing religious unity. They'll mostly reject, but I'll have a CB. The downside is that it's a -25 opinion with every infidel for every use. Fortunately the whole thing times out after 25 years of not using it (quite a few modifiers have no timeouts, just slow decay, they can be seriously annoying), but I'll need to wait a while for authority to accumulate anyway. Another upside is that it gives just slight discount on wargoal, so I can convert primary war target up to 133% warscore, and that's actually quite a few countries.
I got into some such fights, and that brought Damietta and Ming tributary Anxi into it. I hoped I'd be able to cancel Anxi's relations with Ming in the peace deal, but no such luck.
At the same time I had to deal with Pannonia as soon as possible, and they brought in France. Fortunately now that I actually remember how to play this game, I stackwiped French army without too much trouble, and did similar things to their navies even though on paper theirs was larger.
One thing I really wish was possible was somehow hiding labels for all neutral armies, so I can actually see all the enemy stacks. CK2 does it, even though there it's actually really awful and makes raiding harder - as neutral armies go instantly hostile, so you really need to know where they are.
While I was fighting infidels after infidels Byzantium attacked Sinope - infidel vassal. Their timing was pretty smart. I had no easy way to send the troops - Byzantine navy was stronger than mine, as they've proven in two big battles, and I'd have to siege my way there through many forts even if I committed everything from day one, which I didn't. In the end, since I wasn't warleader, Byzantines just sieged one OPM, and got themselves a second imperial vassal.
At least I got huge relationship bonuses for actually doing my job and defending empire and I managed to convince 4 countries to joined the Imperial Cult - including (with some serious diplomatic shenanigans) Bavaria, who'd otherwise be far too big to flip by any war.
Meanwhile France got Sardinia as tributary state in another war. That's total of 8 provinces held by non-members.
All that leaves just 6 infidel vassals, down from original 95 - Algiers, Galich, Crimea, Sinope (under Byzantium), Ulster, and Itil.
That's ETA for unification about 1540. Or it could happen even faster if I removed a few more infidels and pushed back against France, Byzantium, and Deccan. I could maybe finish it before next era starts in 1530, so I can face Ming without distractions.
I still want to attack Mali for gold mines and Maya for Caribbean colonial nation, but I was just so busy all the time.
My armies are finally getting artillery, so sieges should be a good deal faster.
Country of Kaffa off the map declared independence war against Nubia, which turned into the most epic war so far. Attackers were: Kaffa, Deccan, Egypt, Rajastan, Ajuuraan, Mysore, Gondwana. Defenders were: Nubia, Khiva, Baghdad, Arabia. Both side had bigger army than I do, by a significant margin. All for a 15 development country.
So far Kaffa is winning. They're most notable for having the last Chrisitans anywhere, but their overlord made them Confucian, so not sure it will last long enough. Then again, Confucians have just the weakest missionaries of anyone, so maybe I'll find some when I arrive.
Both France and Ming's tributaries are meddling in imperial affairs
This was once entire French army
War of African Colonialism
Too many infidel distractions to be able to deal with Byzantium properly
And now we have truce until 1483
ETA for first reform is 1480, so I'll have some sweet CBs on them
Great Kaffa War for Independence
Empire and its 8 missing provinces