LOL - forgive me for not reading the earlier portions. I just took a fast forward to the back. If that's the truth, then some group must seriously be signing off on some horrible sh*t. Here's hoping there's something at the OS level than can be done to take care of it.
Meanwhile, I'll be hugging my iPad Pro 12.9 3rd Gen a little tighter.
EDIT: Just saw your video, and it looks normal to me. Some of the videos people are post of "jelly scrolling" looks pretty bad. Honestly, I should just shut up and sit in the corner.