1. You can find the latest build here
https://xdaforums.com/showpost.php?p=75442986&postcount=12526
2. Yes. If you're on 6.0+ version of radon. Then just flash directly to update it. But if you're using the older one. Restore your stock kernel first by dirty flash your rom. Alternatively. If you encounter bugs. Then clean install is recommended
sorry for double post
1. thank you very much.
2. which part i should backup from twrp? and what do you mean dirty flash?