IT's been a while since
@dougfitz and I have had a chance to disagree about TSA regulations, so I'll take a shot at this.
First and foremost, the TSA regulations themselves say nothing about hiking poles. They say that ski poles are prohibited and walking aids are permitted. The TSA blog or facebook page says hiking poles are not permitted, but that is one person's interpretation, is not legally binding, and obviously other TSA people disagree. It would be very nice if TSA would change its regulations to make it clear, but they are not likely to be consumed with interest about this issue.
Back from another camino, I have now carried my poles yet again through TSA in the US and through the Madrid airport to transfer to a flight to San Sebastián. Just for the record, I carry my poles (collapsed) out in the open for all of TSA to see, and no one has ever batted an eye. I have done this now more than 25 times and through many different US airports, both when going to the Camino or when going somewhere I will be hiking. I am not trying to fool or deceive anyone, they are in plain view when they go through the screening machine. I have read one report on this forum from someone who has personal knowledge of someone who was not able to carry hiking poles on at a US airport, so there is some risk. I always carry a duffel bag stuffed in my backpack so that I can check them at the last minute.
This year at the Madrid airport, I had to leave the terminal and go over to a different terminal to mail something, because the only post office is in T1 and I was flying in and ot of T4. Coming back through, the security agent asked me about my poles (first time in 8 or 9 years that I've ever had a question) and called over her supervisor. Her supervisor asked me if I needed them to walk. I explained honestly that I was going to walk the
Camino de Santiago and that I would have problems with knee pain without them, and he waved me through. But again, I had my duffel in case of a last minute problem.
So, my experience may be different than yours, but for me the risk of having stuff lost on my way to the Camino (as happened in 2010 when I last checked my poles) is worth the risk of having to maybe check them at the last minute.