Hello, nice to see other people with the same chain of thought !
A close subject was also discussed here.
If you know other relevant threads or people working on something, let me know.
I have a ESP32-S3 box for more than a year, and never had time to open and test it… I would also like openHAB to support its audio capability.
But i’m not so sure that it “wouldn’t be to hard to add”, though 
seime, author of espHOME binding says that the binding is open to contrib on this subject.
I’m still working on the Wyoming protocol add-on for openHAB (low level java classes for audio input/output are done, but not much more unfortunately), but I definitely also think about other solutions like the espHOME devices, or the Home Assistant Voice PE (assuming they are using the same procotol ?). Not enough time ! 