Prevent FPS From Exceeding 30?

[Adeno]

(This should go to General... no idea how it ended up here)

I noticed that there's an option to "Prevent FPS From Exceeding 60" in the emulator for pc, but what if I don't want it to go over 30? It's just that at 60 fps, the game runs at double speed. I tried using the Alternative Speed option and setting it to 50%, but it seems to garble the audio.

Normally, the game I play runs at only 30 fps and everything moves normally, but during a specific scene, it triggers some kind of glitchy turbo mode that doubles the fps to 60 and makes the game ridiculously fast that a timer that counts down from 3 minutes can be finished in just 1:30 min of real life time.

Thanks to anyone who can give me tips on how to change that "Prevent FPS From Exceeding 60" into just not exceeding 30.

Maybe having a 30 fps max option would be nice to have in the next version of the emulator for pc.