AV1 isn’t needed yet, because its only really being used for live streaming like youtube gaming at the moment (Plex itself only started supporting AV1 in December). That might change in the next few years, depending on if the scene picks it up as a technology, its just a case of whether you want to future proof yourself. Of course, given how cheap these mini pcs are, you might be as well sticking with the N5105 now, and then picking up an N100 (or even whatever it’s successor is) in a few years time. If you do end up running proxmox, you can always cluster them together, so you can keep using the old one alongside the new one. (Because they’re so cheap, I actually have three of them in a little cluster, so I can patch and reboot each proxmox server without downtime to my plex server)