[boomer_joe]

Isn't VLC an option for playing local files and available in the App store? You could sync the folder with iCloud.

[nexo-v1]

It is available, but the last time I tried it, I was only able to select specific audio files for import. I couldn't import the whole directory at once

[skydhash]

There’s a VLC folder inside Files (iOS) where I dumped the library. The nice things is that it plays opus (my lossy format of choice).