Hi Aaron,
If using Tomcat, in Tomcat's server.xml, you can add the following inside your <Context> for Orbeon Forms (if you don't have one, define it):
<Parameter override="false" name="oxf.resources.priority.0" value="org.orbeon.oxf.resources.
<Parameter override="false" name="oxf.resources.priority.0.oxf.resources.filesystem.sandbox-directory" value="/path/to/your/resources"/>
With this, Orbeon Forms will first look for resources in /path/to/your/resources. So you can create a /path/to/your/resources/config, and put the properties-local.xml in that directory. This way, there is really nothing inside the orbeon.war you need to change.
I hope this helps,
Alex
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