I used Philosophy to get Mathematics, which means that the AU mod did not appear to have its intended effect on Philosophy for me.
Still it was far from a no-brainer. I was aiming for Monarchy, but Japan already had Polytheism. Sumeria had Map Making, Code of Laws, and Literature. So my choices were a) research something that the AI already had at a discount (probably Polytheism), b) try to get Philosophy first, or c) go for Mathematics. Since Sumeria was researching much faster than me, I thought about it long and hard before I chose to research Philosophy. If Sumeria had beaten me, I would have wasted precious time towards my Monarchy goal.