I'm interested in how the listening test process of the presets was originally organized. Was Dibrom mostly doing the listening tests? Or was it a small group of trusted people outside of the LAME development team that helped Dibrom test? Basically, I'm wondering to what extent community support played a role in the development and testing of 3.90(.x).

I remember that there were public listening tests for different settings/versions. I 'found' this community by stumbling upon one of them (this was back in the r3mix days). But I suspect most testing was done by Dibrom himself.

"Ahead MP4/AAC developer" ???

That one slipped by me. I must not be paying very close attention these days

I was happy to see that as well