Hy.
Lineage is very good, but really I have a battery drain too. I think in the XDA forum, the dev works to create a ROM 64 bit and it is 6.0 base. Take a look.
I was using the en.miui global beta, but before long I had the screen "just a sec" when I closed the browser/facebook. Today, I installed miui 8.1.1.0 stable from xiaomi.eu today to test.