Also worth noting that most (all?) ESP32s have dual cores.

I recently implemented a beam-forming microphone with LLM transcription (offloaded to a browser model)[1] and was able to get all the beamforming and noise cancellation DSP code running on the second core along with the UI, while the and webserver that streams audio uses core 0.

I don't use SIMD myself, but it uses esp-dsp which is already using it.

[1] https://github.com/nlothian/earwing