Bangle.js to ESP32 via BLE

but it's quite a hard, painful job making it reliable. It's definitely not something I think many people would want to take on as a fun thing to do in their free time!

Unfortunately true for all other BLE platforms. Could be relatively easy to build Espruino for any random platform and get GPIO,uart,spi.i2c working but getting BLE stack working so that Espruino BLE API works is major effort. Maybe some port of the api to generic HCI protocol and then linking with HCI support from the manufacturer SDK could make it reusable (but probably more bloated)