For most cameras you are correct however see all previous discussion in this thread regarding the Mavic 4 Pro's dynamic range expansion feature that requires auto ISO.
Based on my understanding of the context in this thread, it allows for the use of the Mavic 4 Pro's dynamic range expansion feature. I'm not sure if the Air3S has a similar feature.
This is the part I don't think is true. See if you can find a Huawei phone on ebay that was made before they were put on the covered list in 2021... there aren't any.
Preventing registration offers no benefit to the FAA. That just creates involuntary civil disobedience. Any drone already previously approved with a compliant serial number should continue to be registrable with the FAA, unless retroactively...