Could the XMOS XVF3800 be an alternative to XU316 in future hardware designs when XMOS has not (yet) release open-source firmware?
Could maybe the Open Home Foundation convince XMOS XVF3800 firmware under XMOS PUBLIC LICENCE so ESPHome projects can use it?
For the official reference hardware from XMOS see their XK-VOICE-SQ66 4 microphone development kit / evaluation kit:
XVF3800 is similar to XU316 in concept but higher-end + supports 4 microphones (for either a square mic array or a linear mic array) and uses those and XMOS’s proprietary “state of the art” real-time DSP voice processing that combine AEC (Acoustic Echo Cancellation), de-reverberation, noise suppression algorithms, multiple adaptive beamformers, and AGC (Automatic Gain Control), which in practice apparently means that it will work much better at capturing clear high-quality speech in a big noisy rooms (where many people are talking at the same time) when compared to solutions based on the XU316 chip.
You may have heard about the new ReSpeaker 4-mic board from Seeed Studio based which is has this XMOS XVF3800 chip instead of XU316:
For discussion about ESPHome integration for ReSpeaker XMOS XVF3800 using closed-source firmware on the XVF3800 see this thread:
For reference, ReSpeaker XVF3800 can be flashed and used similar to XU316 but today it needs closed-source binary blob firmware images:
PS: Alse see these two discussions about XVF3800 veses XU316 which seems to indicate that it is same physical chip with only a difference in firmware. That is, they speculate that XVF3800 SKU look to just include bundled license to use XVF3610 product software closed software: