One thing I have found out is that disabling MIUI optimization in the bottom of developers menu, can reduce CPU strain since it only forces CPU to wait for every app so animations could be smooth like on iPhone.
And without changing governor I can get 4h of SOT without problems, using MIUI EU...
Xiaomi mi4c is working fine, I will test battery today after full charge :)
Also I did update through TWRP and then Dalvic cache clean and everythng works, apart from rare force close from google mail and hangouts.