Hi Nisgeis!
Your mod does indeed improve the AI. After I toned down the effects of the Thermal Layer a bit I've even had (a little bit) trouble shaking off a DD.
But I think the escorts' definitely need to get better at spotting you visually. I was evading at periscope depth (to test out your mod) and although they pinged me alright, I had my scope sticking out of the water the entire time. They didn't fire a shot at it. It seems like they don't want to use their guns at all while pinging or listening. In fact, they had all their guns pointed in the opposite direction of me.
Another indicator that this is a problem was when I ordered my boat back up to periscope depth after deep diving (the fiends actually started DC'ing me! Thanks to you I reckon), my stupid planesmen broached the boat. The entire sub became visible at one point yet the DD (was about 1km away) just kept on circling lazily without acknowledging my presence.
Still, thanks for the tweaks. I wouldn't even have seen a DC attack without them.
Also, consider toning down the thermal layer. It just completely baffles the poor short-bus AI.