

Put it on its own VLAN or guest SSID in OpenWRT, then add a firewall rule that only lets your client subnet reach it on 631 and 9100. Block WAN for that zone completely. AirPrint discovery needs mDNS across zones, so you’ll want umdns or avahi as a reflector, and that’s the part that usually breaks. I’m building a home box that does this by default for IoT stuff. Would you want it to just work, or would you rather see the rules?
If nothing’s exposed and it’s all behind Netbird, you don’t strictly need it. I still would, because apps like Vaultwarden’s web vault won’t load without a secure context. A wildcard cert via DNS challenge is a one-time setup. Everything else is optional.