Flashing custom is always your risk. It doesnt matter what is the cause of your Problem. You have to know...
I think we will have a useable build of custom oreo before we receive the official stock nougat.
This is the best rom for the G4 so far. I use it with the nova launcher prime and it´s really fast, smooth and stable.
Open the Explorer Folder on your pc or laptop in which your TWRP.img is placed. Open the terminal or cmd with press Shift+right Mouse Button.
Flashed it right now. Goes really fast.