My last game, I'm positive in 2.2 I can unite Africa, simply because throughout most game I had no navy because I HATE gathering every single ship after building them, so couldn't invade British Isles and France properly, navy rally points will help ! + was way too peaceful in early game. Also bad luck with Japan getting Congo, they were in my SoI throughout the game, so couldn't do anything about it until they became GP in 1925.
Also, only 1 province is still colony, that is Negele, because for some reason no one wanna migrate there. Every other province turned into state and economy running on Laissez Faire throughout whole game, because party loyalty ends up making Voortrekker party unbeatable, they were winning with 60%+ every election since 1840s..hope this gets nerfed in next patch.
Also was getting quite decent immigration throughout whole game, usually 1-2k but sometimes peaked at 10k+.