This was easier than I thought.
1. Become a developer and switch to ART instead of Dalvik runtime. I had no luck with Dalvik but worked on first try on ART.
2. Go here http://forum.xda-developers.com/lg-g3/orig-development/root-stump-root-lg-g3...
is someone working on gsm patch for cm10 jb ?
Neo's Mean Horsey face and rage come with a GSM patch you can download, and it works I have tried it.
Shrikes build I think has the GSM patch build in but I have not tried it yet....
If you are rooted:
Install an AOSP rom (Liquid 3.2 is what I like)
Install IMO's latest kernel
Choose the battery saving option.
Underclock to 768
If you are not a gamer there will be almost no performance problems and yo...