The choice of formatting of the SD card should have no effect on the musical performance. The formatting is specific to the computer platform in the device, so that it will be recognized by the device, and if the card works in your device the formatting is fine and you're good to go.
SD card formatting
I have a 128gb SD card (SanDisk Ultra) which I formatted for a Hiby R3 Pro Saber (DAP). I chose exFat with a 128K Allocation Unit Size. My music files are Mp3 and FLAC. Is 128K (and exFat) the preferred configuration, or should I re-format to another? What would offer the best (musical?) performance? I just joined this website, so my apologies if I chose the incorrect discussion-group. Thank you for your time.