Yes, I'd forgotten about that--that's an option too, though it obviously wouldn't work with anything that would get a Let's Encrypt cert.
Ideally this will be done in your router, but I don't know how many consumer-grade routers support that feature. If you use (or start using) Pi-Hole, you could set it up there. I know my pfSense box does, though. Otherwise, the hosts file would have to be the way to go.
My router is a Sophos XG running on a mini PC (well beyond my capabilities and needs).
I tried the Host DNS naming of the NC on the Sophos (but - you guessed it - without success ).
Anyway thanks again.
I'll do more reading and see what comes first : either my knowledge to be adequate to manage it or a script that installs the NC with a selfsigned cert and can be reached typing it's IP (probably the 2nd, if if it take a lot of time :D )