That’s why self-signed and "local signed" should be distinct concepts, IMHO. The .local domain is already special cased, and could provide a different UI path more akin to how SSH works. AFAICT, you can’t get a https cert for a .local domain, so it’d not break existing https security model. It’d provide a more secure way for apps like syncthing to provide a secure local UI as well. Getting browsers to accept my self-signed certificate is a pain and makes people just use http.