I don’t know, maybe people think I am weird, but to me the whole reason why you have a NAS is to make things simpler.
It would be much lower cost and much more compute horsepower to simply buy a solid i9 ultra computer, put Linux on it, add a raid card and GPU and you are off and running. Now load it up with drives and you have a do it yourself NAS. All the command line stuff you want. And you spend a lot less money. Probably somewhere between $1000 and $1500 less.
The whole point of a NAS to me is to use the UI and the interfaces provided so I don’t have to worry about stuff working on the command line.
Now, I don’t disagree with your point that if QNAP has the ZFS utilities there, they should work. I am just saying maybe there’s another step in there that you are missing.