I installed this new ROM via so flash tool whit out any problem.
Download and extract new ROM , download sp tool I done with version 1804 windows.
Keep I'm mind all USB drivers in my case are done and installed earlier. I done from android 7
Do factory reset before keep phone clean.debugging on, trough development option. Phone off,
So open sp flash tool load scarlet , press download,connect phone to PC holding volume up button till it stars to load new ROM , below yellow line on so tool starts to load then wait till its done. , after its done close sp tool disconnect phone. Do another factory reset , thats it....
Battery improved significant, its hold alot of hours, fast charge works, finger print works, face unlock works, camera improve significant to. Very nice very happy. But only 1 concern , from where this ROM come, who done it, and or it safe to use... I do not know , but phone working very smuth , blothooth everything is like proper android ROM , which BC could deliver official.