I’ve been told that LAME encoding is not as good (quality-wise) or fast as the Fraunhoffer encoder. Do you think this is true? Is there a way to use the Fraunhoffer encoder in Audacity?
No, it’s not true. The Fraunhofer encoder was abandoned years ago. It think the “latest” version was around 2007. Lame is still under development and has made significant improvements over the past decade, particularly in VBR encoding.
Audacity is able to use command line encoders: Exporting using an external encoder program - Audacity Manual