I've looked into this, and found nothing. One can surely repurpose the case and speakers, but the microphones are soldered on-board, and the board is not hackab

I've looked into this, and found nothing. One can surely repurpose the case and speakers, but the microphones are soldered on-board, and the board is not hackable and needs to go. To best of my awareness, there are no ways to load a custom firmware on a newer Echo device - they're locked down pretty tight.