http://nmap.org/book/man-port-scanning-techniques.html - this page lists technique that allows to probe if a UDP post if closed. It would be awesome to see green button that lights up when you complete IP entry in configuration dialog.
I’ve tested with curl and I got:
So, at least 30 seconds, I guess?
As said, rather make it configurable. This is a real-world system…
I don’t see how allowing users to at least review the settings they have made could be considered un-Material. Yes, a URL might be technical, but they had to supply it in the past in order to sync to that URL to begin with
If anything it would be un-Material to not allow a user to see the info they provided in the past again.
Now you’d have to maintain a separate list outside of the app of which account name is connected to which server.
Within the current layout I’d say at the top of the settings of the account would be the most suitable location. It could be nothing more than static text if you don’t want to provide a way to change it. There’s a risk you’d need to cut the URL and continue displaying it on a second line, but the settings screen is not something you stare at often nor for a long time. It maybe being a bit less pretty but I’d say actually having the info is more important than that.