i discovered how you can change the port number of the host, but i don't think it's possible to change the hostname. Which makes a bit of sense, otherwise you could run ArcGIS Runtime as a server to the outside (Internet). Still, i'm curious how Esri developers debug ArcGIS Runtime. I noticed that the status updates or feedback through the C# code is not always complete and i'm missing important information. Listening/watching to the actual HTTP traffic would be really helpful to get things working more quickly.
to change port edit arcgisruntime.json
{
"serverExe": "bin/ArcGISRuntime.exe",
"args": [ "port=1337"]
}