It's not supported in older versions of C2, so no, you can't do that. Also, it shouldn't be slower on the newer builds unless you change anything, did you run the exact same project in both versions and experience difference in FPS?
Newer versions of C2 generally improve upon the performance of prior releases. Are you sure you can measure a consistent difference and you didn't see a one-off result? (If another app becomes busy in the background, for example, it can make your game temporarily slow.)