That's why they call it development and it is free to you--
I question your comment "every" release is broken
If you are about talking cyanogen in general, the nightlies work fine for me and most folks
If talking about this one, READ xkonni's comments in his CM10 thread. He said he probably uploaded this too early. But, WE are appreciative he did so we can get a taste of JB4.2 as it gets DEVELOPED--
Except for camera and bluetooth it works very well, not a daily for most, but not intended as one--
The technicals are beyond me to answer that part of your question, but enjoy these builds and respect the hard work the devs put in to these roms, working 100% or not.
ATT Samsung Galaxy S4/Rooted/TWRP 126.96.36.199/Wanam Xposed, or Gravity Box/Long Time MultiRom Flasher/Waiting For The Note 4--The Game Changer