Maybe I'm wrong but in the screenshots of other devices I see three available output options: the native audio API OpenSL ES / OpenSL ES HD, and the Hi-Res (Experimental) via hardware.
The Huawei Mate 10 shows the OpenSL ES and the OpenSL ES HD options as seen in the screenshots of my previous post, and in your screenshots, but not the Hi-Res Output (Experimental)... Or is it possible that I am making a mistake and should not expect a Hi-Res option via hardware?