After two days of using the phone here are my observations on audio:
1. The ONLY app that can play PCM, DSD and MQA to the full potential of the ES9218P DAC is the stock LG player.
2. The stock player interface is very poor and limited but the quality of audio output is excellent
3. MQA files need to end in .flac or .wav extension for the stock player to play them correctly
4. Most players still use an older Android API for querying the abilities of the DAC. This only allows one DAC to answer and it is always the Qualcomm DAC, not the Sabre DAC. This results in the app decimating and converting all audio to 48khz PCM even when the phone does output via the Sabre DAC.
5. The new FIR filters interface does a capable job of smoothing out digital ringing.
6. High Bitrate music files placed on the new Sandisk 400GB high-speed MicroSD card were played perfectly
Other music players tried:
1. USB Audio Player Pro
2. Onkyo HF Player
3. Black Player
4. HiBY Music
5. Google Music Player
6. Amazon Music Player
7. Tidal
8. PowerAmp
9. VLC
10. Foobar2000
11. Pi Music Player
12. jetAudio HD Music Player
13. Neutron Music Player
14. NRG Music Player
If you would like me to test any other players for bitperfect output, please let me know. I record directly from the output of the V30 into a Sony PCM-D100 high-resolution digital audio recorder at the highest possible bitrate for the encoding used on the source. I then use Adobe software to do a comparison of the digitized output captured to the original file. There are always a few minor anomalies due to the nature of digital to analog and analog to digital conversions, but it is easy to spot when a decimation or digital to digital conversion was done during output.