Yep! Thats correct! The whole system is gonna be within the J-Box, it is fully capable of working without the External unit, the ext unit just makes it easier to control it!
Yea I got ya! What I actually do is hold a piece of paper under where im drilling to catch all the burs, you don't see it in pics because I basically create a photo op of what im doing since i have to hold the camera with one hand and the drill with the other!