Fwiw, bought 3 MBP16 on release a year ago (one for my partner personally, one for myself and a coworker for work) and the one that was for me had the exact same issues you described with kernel panics, spontaneous reboots, anger at trying to use a dock or an external monitor (tried to use diff cables, didn’t help). Other two had no issues whatsoever. After 3wks, took it to an Apple store and swapped out for a new one and never had a problem again. They didn’t ask many questions in the store, but it might have been because I had purchased >20k in gear in the past month.