Greetings and thanks,
Your articles and video are very helpful. None of this is documented by Gigabyte that I can see. Strange that they put the VRM/MOS fan under the cover that houses the backplate connections, but then again where else would they put it. The video states the fan is capable of 10.5K RPM.
In my opinion this is a questionable design as the fans are prone to failure, or screeching as in your case. It's probably covered under warranty but as you said, you'll loose your board for a few weeks. (For a fan) This is not cool.
I couldn't see the model number legibly, but you could probably source one yourself and replace. This design alone would give me pause. I don't care how great the board is, how flexible, powerful, over clock-able, etc. This type of fan design will haunt every person who buys one of these boards at one point in their ownership. Same for the chipset fan.
Beautiful board and fantastic performance, but inherent weakness that might cripple or render it un-useable with the burden of out of warranty replacement on the user. I could never recommend this. If I did, I would make sure that the person was aware that two points of failure exist.
If you look back now, this type of design hasn't been used in consumer MB's in about 12-15 years. First it was heatsinks, then aftermarket fans for your north/south bride and video cards. Then, GPU manufacturers figured out the potential of cards with coolers and what they could do. Great things happened.
I am a former Asus user who jumped ship after many (many) years. I have never looked back and fully support Gigabyte.
Given the amount of work needed to disassemble, and the potential for downtime, I personally would skip this design. Hope you find a workable solution.