So you say that you didn't notice the laptop temperature getting any lower, but this isn't too surprising to me, since this thing is going to be highly thermally limited.
I suspect that your setup is doing something, but the thing it's doing is allowing your laptop to sustain a certain performance level for longer. So what I would look at is some performance metric like e.g. peakflops() in a loop, or a video game FPS counter, and compare with and without the external fans.
So you say that you didn't notice the laptop temperature getting any lower, but this isn't too surprising to me, since this thing is going to be highly thermally limited.
I suspect that your setup is doing something, but the thing it's doing is allowing your laptop to sustain a certain performance level for longer. So what I would look at is some performance metric like e.g. peakflops() in a loop, or a video game FPS counter, and compare with and without the external fans.