It might help to lower the audio sample rate to decrease the amount of data flowing through the audio buffer. You can usually cut it in half without much difference, it’s noticeable, but only just.
In retroarch.cfg set the sample rate to this
audio_out_rate = 22050 I think by default it’s 44100.
Idk if that will work for you, it’s just a theory based on digital audio knowledge in the windows world, but things are working on my end.
Edit: if this isn’t the liberto version, then I’m not quite sure where you’d change that.