I am wondering if anyone has looked at sources for the Composers Desktop Project, these were made open source a few years ago and are written in C so I think might be interesting candidates for adapting to Axoloti.
The only thing is they are all offline processors and so will need to be adapted to work in realtime DSP but there are some interesting processes worth exploring, especially FFT ones based on the Phase Vocoder.
I am new to Axoloti and to learning C so don't really know how to do this myself (yet!) but I thought it might be worth mentioning here and ask if anyone has looked it.
I have been using the CDP offline processes for a while so do ask if you want to know more. Cheers!