It's up to you, but the secure way of doing it is by creating your own handle - because then you can disable the bluetooth UART for production and you know that all anyone will be able to do via bluetooth is to change the LED brightness
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
It's up to you, but the secure way of doing it is by creating your own handle - because then you can disable the bluetooth UART for production and you know that all anyone will be able to do via bluetooth is to change the LED brightness