Hi Martino,
In order to have a better understanding of your problem, could you please share the following information:
1) Which kernel version is used for your Kit Kat build? Is it the exact same one as for Jelly Bean 4.3?
2) What happens exactly when running the SGX implementation without the workaround?
3) Could you send both logcat and dmesg logs in that case? Where does hwcomposer crash?
Best regards,