BTW, I think you need to have a correct concept here.
Make sure what platform and what release you are referring to in each post.
For example, you said you saw a post like this " https://forums.developer.nvidia.com/t/an-error-occurred-using-the-method-of-flashing-with-initrd/210667/6 "
But obviously, this post is using rel-32 (jetpack4.x) because jp5 was not release at that time… And you already told us you can flash nvme with jp4.6.2. So, what does that mean? It means you don’t need to refer to that post at all. Your issue has nothing to do with it.
And it is pointless to say “oh there are lots of issues there”. My point was there is not much user reporting "jetpack 5 + nvme " case…
You don’t need to try to persuade us there are other posts. I don’t care. We just check and focus on your issue first.
Also, the document does says it needs to use usb device mode… It is just not obvious.
Usb device mode means you can see 192.168.55.1 interface.
