@ConorONeill, I am going the same route as you. I ordered the Raytac MDBT42Q BLE Module and I am planning to put a breakout board together once I receive it.
Q#1: Which binary should I use?
Q#2: Is the bootloader shipped with the firmware provided by Espruino?
Q#3: What software did you use to flash the firmware on yours? (I have Segger programmer)
A little background, I built prototypes before and programmed BGM111 directly using Simplicity Studio but I got very interested in using JS instead of C.