SouthPark Unfortunately, I can’t still play your audio file in my iPhone 15 with iOS v17.
Not sure why your NCH software only have 0-4 compression level option compare to my Audacity with 0-8.
I can see that you have enabled shape dithering and I am not sure if that is turned on in my audacity settings by default (might check it later).
There could be many variables to test for compatibility since FLAC frequently release improvements (https://xiph.org/flac/changelog.html). There is also native and ogg flac format adding to the complexity.
Apple won’t prabably care much about FLAC updates as they have their own ALAC to encourage or perhaps force their over 1.5 billion users to use their own lossless compression digital audio.
So, I will just use my laptop to open your flac file if it doesn’t work in my Apple device.
BTW, thank you for sharing. I like your audio recording from your P-525/P-515 which is much better than my old yamaha clp-480 and p-255.