Don, I've actually spoken to Jesse about this on the phone, so I probably am basing some of my thoughts off that. Most important is the fact that he can't CHANGE it. Changing the numbers on CEBIS don't change how fast the head drops or raises--in manual or in auto. That is a huge red flag that something is wrong--beyond the head hopping.
Yes, the numbers I gave are for full range; however, I disagree the video is not clear. That head is moving up and down way to quickly, even for just in the height range. Being with Headsight, I look at a lot of "ahhc videos" and to me, its like somebody is running the video at 2x or 3x speed over normal. The only other time I saw something that looked like that was on Gleaner S series machines that had uncontrollable hopping. Sure, turning the sensitivity way down may stop the hop, but it will also make it very non-responsive to changing terrain in the field. Thankfully, the MacDon head may be the most forgiving head out there....
I do hope that checking accumulator pressure may help matters. However, I can't think why incorrect accumulator pressure would make it so you can't adjust the manual raise and lower rates. Very interesting to find out what happens.