So it seems that TSA Bob is suggesting that separating pieces of your custom electronics may help your luggage get through TSA screening. Since this device was found in carry-on baggage I don't know how much that would help. I often travel with custom and semi-custom electronics in my checked baggage and I've never had a problem (although I regularly find the "searched by TSA" card when I reach my destination). A couple things I do:
-Put custom electronics in my checked baggage whenever possible
-Put the parts in separate containers whenever possible
-Separate batteries, antennas, and other accessories from the devices
-Try not to travel to Phoenix (nothing to do with custom electronics or TSA, I've had two bags seriously damaged at PHX)
Also, be aware that "rubber-ducky" type antennas show up as a thin metal blade/wire on x-ray. I've had my carry-on's searched a couple times because I forgot to put an antenna in my checked baggage, although it's never been a problem once I took it out of the bag and showed it to the agent.