All of this is largely irrelevant to our prior discussion and we should not lose sight of the forest for the trees. I agree with you that slavery is economically inefficient and attempting to train educated slaves is even more economically inefficient. Our disagreement (if any) are entirely over the fundamental nature of the forces that lead to the end of slavery.
Your argument was that technological progress that helped end slavery and I agree with that. However, technological progress is simply a function of applied knowledge
I agree that technological progress is based on knowledge derived by sciences in general and individual scientists specifically. But that's not your original point. Basically, you claimed that slavery had been banned due to rising morals in human societies, broadly speaking, and that was the primary driver independent of technological advances. As to me, this is debatable. I'm more inclined to think that the higher morals were themselves a result of higher living standards, but these improvements had evidently been due to economic factors...
And the latter also worked toward universal abolition of slavery (since it got in the way), though it is not evident