I have a customer using open liberty on Azure Kubernetes Service. They have a server.xml which refers to properties files using the mechanism. Their setup is similar to this question:
My related question is: how do you get the scanInterval to actually cause the properties values to be reloaded from properties files read using the plain old Java System.getProperty()? I realize that properties files loaded from the classpath are not dynamic (as shown in this ten year old question: How to reload properties file in java - Stack Overflow), so the scanInterval attribute seems kind of irrelevant.
It seems to me you'd need to send a UNIX signal (SIGINT maybe?) to Open Liberty to cause it to restart.