I flew several airplanes, so I go the "portable" cushions years ago and used them even on the airline. I loved the effect on my back! the lumber support piece could be used separately from the seat portion. I used the lumbar portion in my partachute for the Skybolt. It worked well for back support and would not interfere if I had to use the chute.
As a disclosure, I am responding without looking to see their current product offerings. I still have it, I've used it in my car as well, but in the last few years, I have not had the back issues as before.
Based on my past experience I would not hesitate to recommend it or to buy one again if I needed it.