Maven and multiple SOAPUI files

I'm using the Maven SOAP UI plugin to run tests. It's all good, except I have a directory full of SOAP UI project files I need to run tests for. It looks like the projectFile configuration for the plugin only accepts a single file.

How can I get Maven to utilize more than one SOAP UI file at a time? Is there a config to the maven plugin? Or can I include multiple SOAP UI files into a master file?