I currently have a mess of wires from a le1 hookup board to an Arduino Uno. This works, but barely. The le1 is not 5v tolerant per the datasheet, but it is tolerant 98% of the time, the other 2% will kill it. Not to mention the wires and the extra board.
To make things better, I am going to use an Arduino Pro Micro 3.3v and use that as a programmer and UART bridge. Combined with a cheap module breakout, this should make be a big improvement. Programmer software here.
I might design a dedicated PCB for it one day.