Shawn,
I have never used this plugin but can't this just be included in your suite xml file ?
I have a whackier way of doing this which doesn't involve a change to the failsafe plugin code base :) [ yes its for sure a whackier approach ]
You could perhaps leverage the filtering option that is available in Maven wherein based on a JVM argument you could flip the value based on a JVM argument perhaps.
Your suite xml file could look like below :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Suite" configfailurepolicy="${policy}" data-provider-thread-count="20" group-by-instances="false"
parallel="methods">
<test name="Test">
<packages>
<package name="com.test.testng.*"/>
</packages>
</test>
</suite>
Your pom file's resource filtering section could look like below
<testResources>
<testResource>
<directory>src/test/resources</directory>
<includes>
<include>configfailurepolicy.xml</include>
</includes>
<filtering>true</filtering>
</testResource>
</testResources>
Your pom's properties section could look like below :
<properties>
<policy>continue</policy>
</properties>
And you could execute your tests using a command as below
mvn clean resources:testResources test -DsuiteXmlFile=target/test-classes/configfailurepolicy.xml -Dpolicy=skip