How does Tirtha Yatra change the emotional register of the album — does it feel earned by what comes before it?

I feel like this one doesn't really change the emotion of the album, i feel songs like nose to the grindstone, tomcat and the dandy have much more emotional impact on the album

I'd agree with that. I do think the subject matter paints a different side of Tyler than the other tracks up to that point. Tirtha Yatra shows that he's not just stumbling his way through life, but actively trying to learn and understand. I especially like how he makes note of the Hare Krishna which then shows up as the chant in Tomcat And A Dandy. It felt to me like he found something in Hinduism that he's then bringing to his songs after.