Sorry, if Canon is not willed to repair this problem, this will be my last Canon.
Can you reproduce the issue at will? If not, does it recur at a frequency high enough to occur in a few minutes of testing by a technician, which is all they'd reasonably spend diagnosing a problem? If both answers are 'no' it's unlikely they'll be able to observe the problem, a prerequisite for fixing it.
The video concern surprises me, though. When the 1D X was new, I came across a bug with the AFMA setting. I called Canon, they couldn't replicate it and told me to send the camera in. Instead, I made a video of the issue and posted it to my Flickr account, then emailed the link to the technician. He emailed back agreeing there was a problem, and said he'd escalate it. Posting the same video on a couple of forums elicited some excellent diagnostic help which identified the cause of the issue (enabling orientation-linked AF point caused AFMA to misbehave). I passed that along to Canon, the issue was fixed with the next firmware. Of course, a key difference was that my issue was reproducible.
Yes, the problem is, that the issue occures sometimes one time an hour, on aonther day just once.
The second thing is, that you own the highend model, and I don´t.
And the third thing is, that here in Germany, the CPS silver membership (as I do not own an 1D... model anymore) is not the same than the one in the US. The service comanies are "invited" from Canon to repair the Cams on the cheapest way. Sometimes getting spare parts from broken Cameras too (had an issue with my 7D 2 years ago. got it repaired, then two month later the same problem occured again. and the service company told me that this time they used an new spare part, not an remanufactured/used one...)