try this one from post #10: https://drive.google.com/file/d/1tCLamw9j07bhRgEd6qhymqUxExazy04c/view?usp=sharing
I can confirm this for both BTU firmwares of Oreo 8.0 from May 1st and 12th.
I can backup data and other partitions in recovery(twrp) as usual, meaning partitions are not encrypted.