I'm currently running Alliance ROM v2.2 with Boeffla 5.1 beta 12 (old bootloader) and USB audio does not work with my HRT Microstreamer USB DAC. When I hit play in a music app the play timer skips through the song a few seconds at a time and eventually crashes. No sound is played either.
It all worked fine on 4.1.2.
Anyone perhaps running stock 4.3 with the new bootloader got USB audio working?