I remember an area in MK that was designated as a "sitting only" section for parade watching. I also remember that once Spectro was over, everyone stood up to watch Wishes which caught me by surprise
There is a 'sitting only - no strollers, no wheelchairs' area on the outside of the hub, between the Liberty Square bridge and the Castle - Right in front of a gazebo-ish structure (hence the sitting only so the Gazebo folks can see). That is the only one I know of, but then again, that is the only section of the parade route I work. HTH!!
In September the center hub was sitting only. It was nice to be able to sit the whole time but we were there an hour before Spectro and barely got a seat. We got up and moved further down Main Street for Wishes since there is a time gap. We needed to stretch after sitting on the ground so long!