This issue is related: https://github.com/espruino/EspruinoHub/issues/16
I haven't seen it done, but I'd definitely find it interesting. Have you seen anything about how to make add-ons?
Yeah, I've done a simple one before. It's just a Docker image. And you build off their base images.
The main issue, I think, as you raised on that GitHub issue, would be working with Bluetooth, but I haven't looked into it yet.
I was thinking of setting up Espruinohub so that send BLE stuff (eg temperature from Puck JS) into Home Assistant. I was wondering if anyone has already tried running it as a Home Assistant add-on? If not, maybe I'll give it a go and see what happens...