We prefer to give assistance in open forum for this kind of problem because other users may also benefit from reading the posts. Anyway, there's nothing more to be gained by seeing the device in a video and i'm sure you're experienced enough to be following the directions and information i've given you. More to consider and things to try:

Clearing the nonvol doesn't completely erase it of course. My earlier question about cross-flashing history was because such attempts often re-map regions and write some semi-permanent data to nonvol that's not 'clearable' but is erasable. Problem is that there is no way to selectively erase the nonvol memory, it must be completely erased. There may not be any material negative side-effects of that, the device will re-create most data correctly for the relevant model/HWID however erasure could result in loss of some features. If you'd like to try completely erasing the nonvol using sd card with 'ergn' text command then read this thread: [Only registered and activated users can see links. ]. First ensure you sucessfully backup the region, read how here: [Only registered and activated users can see links. ].

If you want to try but need help in making an sd flash kit then just ask.