LineageOS

OnePlus3: arm64

TWRP: https://twrp.me/oneplus/oneplusthree.html

Install using TWRP in this order: Reboot after last install:

1. Nightly: https://download.lineageos.org/oneplus3
2. gapps: http://downloads.codefi.re/jdcteam/javelinanddart/gapps
3. SU: https://download.lineageos.org/extras