If you have dead spots, there is no solution. I was on aosp when it started for me. Returned to stock, no fix. Updated to most current firmware, no fix. Tried the update touch firmware in service menu, no fix. Along with dead spots, knock on quit working for me too and I also seem to be having "phantom" touches. Called at&t today and my replacement is on it's way (I'm still under warranty.)
I really doubt this is a rom issue. Its more of a issue with the phone itself. As I said, nothing I tried fixed it. The tech also said he's had several calls in regards to LG's lately.
Sent from my LG-D800 using XDA Free mobile app
PHN LG G2
RCV dr87 TWRP