I previously thought about how Slavery was so entrenched into the USA South that there was no way the CSA would emancipate its slaves in the 1890s (a... oddly common cliché among ACW timelines at one point before I stopped paying attention to those threads on this site). Slavery was in the society and even some internal observers noted how dependent the economy was on slavery by the 1830s. It could not be eliminated quickly without destroying the Plantar class, who basically controlled the state governments and at the same time they refused to think of a future of the institution being slowly eliminated the way it was in the British Empire.
The Southerners knew Lincoln had abolitionist sympathies and were afraid he was the first domino in Emancipation. Well, they were right in a way, just that Lincoln didn't really intend for it to be that way when he got elected. The American Civil war was a long fought out war, and I seriously doubt the South would be willing to give up an institution they fought to bitterly over. My initial thoughts were that Emancipation in a hypothetical CSA is that it would not be possible without another way or at least until not only the generation that fought in the ACW died, but until all their great grandchildren were no longer working age since Slavery was that ingrained in the South.
But then I thought about it. I think there might be one way for a hypothetical victorious south to go under legalized compensated Emancipation. Some people said "If the South did X they could have won" but the odds were stacked in favor of the North. British intervention in favor of the South, although unlikely, would turn the tide around. It's not likely since the British economy was not dependent on Cotton as much as the South would like to think, the fact that the British stockpiled a lot of Cotton anyways, and the fact that Egypt simply filled in the void. The British also imported wheat (or Bread? I forgot) from America and while alternative sources could be found, it would not exactly be cheap. The British were not huge fans of slavery either, although they never forced the issue on USA before the ACW.
British intervention in favor of the South, although unlikely, would likely lead to other European countries giving recognition and tip the odds. It's really the only way because the South could not win without them.
Now here is the interesting part. The British didn't put huge diplomatic pressure to end slavery of US in the 1850s and they likely aren't going to on the South in the short run. But by the OTL 1870s, they were doing it to Brazil, a country with a stronger economy than the South likely would have. It is logical to assume they would be constantly reminding the South how backwards slavery was. Implicit is "I made you. I can unmake you.
And I think the local plantar class might do something to figure out how to reorient their economy. True in the OTL American Civil War after EP they didn't drop it when their choices were "keep holding onto slavery to the bitter end" and "not be victims of scorched Earth." But in an alternate timeline under British diplomatic pressure, seeing Brazil free its slaves, I think TTL South might be able to think about it over a decade (not in the heat of war) and realize that as much as it likes holding Slaves and as much as they believe their racist ideology, the trio of self-preservation, agricultural reform, and long term economic prosperity has to be the better choice.