My Pelican 1510 (carry on maxed size) has served as my seat in many crowded boarding areas. However, it is a two-wheeler and not a spinner.
I have used a porter before and would recommend them as well as I use a check-in sized one as the base of my cart for photo gear on location shoots.

I know the Peli 1510 is rock solid as a seat due to the two wheels and legs set up. I would question the spinner's ability to stay at one spot.