There is now a Official Version of TWRP for the Honor 8
They have now official twrp for the Honor 8
DarkExistence there is no build other then the 304 build
The Official Lineage os build is ready to download https://download.lineageos.org/chagallwifi
The Panadroid Android Team has working 2 months on this build for the Nextbit Robin
And you can now download it.