i dont know why, but the animation in season 2 isn't running as smooth as in the first season.
It is mostly because the renpy version in season 2 requires more CPU power than the one in season 1. I have no problem and they run smooth because my cpu never reaches too close to 100% (you can check the difference with task manager processes tab open while running the animations, just monitor the ProjectPassion process).
The fact that as the development progresses the animations have more quality also can ask more from our machines, dunno if the transition from less DAZ and more blender in the last updates can have an effect too but doubt it, I say that season 2 animations have more quality and renpy version is more recent, that is always the problem with software, as updated they get if our machines don't get upgraded we notice hehe.
In season 2 some animations on sex scenes can eat up 30-40% sometimes even give peaks of near 50% on my CPU {Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz}, the cutscenes rarely go over 20%.
In season 1 most animations don't even require 10% on my CPU, only a few more speed "animated" go a bit over 10%.
GPU power required on my machine is constant in both animations and cutscenes in both season 1 and 2 so that isn't an issue.
Well what you can do is close other programs or applications that are eating your CPU and hope it go down as much so they run smoothly.