With multiple computers on a local network, it would be so much easier to have mDNS/Bonjour support so Syncthing config pages could be visited by name instead of IP.
For example, computer1.local and computer2.local instead of 172.10.2.3 and 172.10.2.5.
On macOS, Bonjour can be used (or perhaps the dns-sd command line utility), while on Linux there is avahi.
Windows 10 just got Bonjour support behind a Registry flag but I think it’s for navigation only, so it (and earlier versions of Windows) perhaps can be ignored for now.
It’s up to the application to register with the system bonjour services, so that part would be in scope. Printers and routers seem to announce their admin guis this way, I guess we could too. However it’s not precisely the same as Syncthing will usually be administered locally, it’s unusual to just drop in a headless Syncthing device in your network and start settings it up from somewhere else. So I’m not super convinced of the utility…