I am always worried when I bring development boards on airplanes. I assume most people are reasonable, but I worry for a few that might not be.
I've brought mini clusters of bare Pis many times before (and other strange contraptions with jumper wires all around), and the only time I was ever stopped for a deeper search was when I left my x-ray shielding bag for film in the same case with the mini cluster.
I brought a 5G Peplink modem (which has 4 external antennas) in my checked luggage and got "randomly searched" by TSA on both legs of a trip once, which I thought was pretty hilarious.