This method is also working for Nexus 5X. Now i can hear sound up to 192khz. I changed ro.product.manufacturer from LGE to Meizu and added empty audio_hifi.conf. So Hi-Res is possible on the Nexus 5X using CM13 but Volume is lower with hi-res.
1. Nexus 5X 2. Android 6.0.1 Cyanogenmod13 3. Snapdragon 24-bit PCM ; Hi-Res Output is on but no audio output. audio_policy.conf