Force MediaBrowser to ac3 audio

I just bought the Serviio license and tested out MediaBrowser. Unfortunately it defaulted to mp3 audio encoding for the clips that I tried to watch. As my ARM NAS lacks a proper FPU it's totally maxed out and stutters every few seconds.
-Dserviio.fixedPointEncoders automatically switches ac3 to ac3_fixed and makes a world of difference when transcoding online media to my TV. Would it be possible to force MediaBrowser to use ac3_fixed instead of libmp3lame?
-Dserviio.fixedPointEncoders automatically switches ac3 to ac3_fixed and makes a world of difference when transcoding online media to my TV. Would it be possible to force MediaBrowser to use ac3_fixed instead of libmp3lame?