I have set up something similar just recently with an OPNSense box running DNS, the WireGuard instance and getting a wildcard Let's Encrypt cert that it pushes to my Synology reverse proxy (Nginx). So from my clients I can enable the WG tunnel only on my internal IP range, setting the internal DNS, so I don't have to have my public cert pointing to my IP. It works once setup for my home net. But for multi-site, Pangolin looks very polished and probably easier to set up.
Is Newt a custom implementation of a WireGuard server? Has it been security audited in some way?