While everything was working fine, it was quite a bit of a mess to look at, so I figured I would do a few small mods to the bubble machine itself to eliminate the external battery holder and get rid of the rat's nest of wires. My objectives of the mods were to do it in such a way that it could be easily reverted to "dumb" operation and pull out as few wires as necessary. I was a little surprised after getting it open that where the leads made contact with the motor there was some heatshrink tubing and there was some silicone like compound on the battery holder solder joints. Didn't expect them to bother to do that on a very cheap device.

Anyways I drilled a small hole in the side, cut the wire running from the motor to the negative terminal, extended the leads, and pulled them thru the drilled hole I also added a reverse-biased diode across the motor leads. The reason for the diode is that although my MOSFET board includes a flyback diode, I would have had to pull out both motor leads plus power and ground to use it. After soldering everything I placed heatshrink tubing on the two wires I extended and potted the diode with hot glue.

After that, I re-assembled everything and the end result was much more tidy. Upon reflection, I should have made the hole in the back vs side as it does it get in the way of the handle, but it's not a big issue. I should also mention that I got my money from HaD and have sent off the board design to OSHPark.