THe facelock ws removed due to the fact it is not reliable. It has been removed from current builds till google refines it and decides to release an actaul secure one that can't be unlocked by a coomon photo grpah or similiar looking people.
Simply because it's concidered a security flaw.
Now if you have installed a leak, you can face the potential of 1. the wrogn bootloader is in place and you won't get the 2 step (1-86 and 1-10)optimization processes before final reboot.
Even if you flash back, you need to change to the default bootloader as well.
031 is the old leak. there has been discussions over the issue on other forums and they figuared out what was causign improper updating .