Of course loxone offers the possibility to connect the miniserver to the internet and also an app for mobile devices to connect to your smart home via internet. The problem is the connection is not as smart as expected. heise.de had a short and a long story about that.
So the first step is not to connect the system to the internet at all. The second step is to have a separate network for the home automation with very restricted access in both directions. Of course I want to use something like ntp ro make sure the time is always correct. But what I do not want is that the system is accessible from the outside.
Another reason to restrict the internet access for the miniserver is that after loxone provides a software update and the miniserver becomes “aware” it’ll start complaining that the software sould be updated. This is acceptable for the people who run the installation, but the normal user should not be bothered with that kind of information.