Scratch this one off the list… mostly.
using the “Bind to IP address” feature in usermin configuration does not have the expected result.
It makes any “redirected” address forced to use the IP address.
I was expecting it to use it the way apache uses “listen” to limit the interfaces on which usermin can take requests.
Instead, it limits the URL/DOMAIN NAME to only being used if invoked directly at the location bar of the browser, while it redirects login requests from virtualmin to use only the IP address and nothing else.
For now, the setting has been changed back to “any address” and that has fixed the user interface problem, at the cost of server configuration.
It’s best to be able to limit any running port-listening app to a specific IP address, regardless of what Domain/URL it is responding to.
Is there any way inside the miniserv configuration to place an apache-like “listen” directive?