I use several different portable devices (aka DAPs -- i.e., digital audio players). Examples of DAP manufs: Fiio, Colorfly, iAudio, Teclast, etc.
Not sure what default OS each DAP uses -- but likely Linux in their firmware. When I use Win to create a Music SD card, I have no issues with any DAP recognizing or playing back. Ubiquitous FAT support, I assume.
About partitioning the SD card ... what's the easiest, quickest way to do this in Armbian ... is there a special native Armbian utility for parting?