The default action is:
<action>
   <actionName>profile</actionName>
   <goals>
      <goal>nbm:cluster</goal>
      <goal>nbm:run-ide</goal>
   </goals>
   <properties>
      <profiler.action>profile</profiler.action>
      <exec.executable>${profiler.java}</exec.executable>
      <netbeans.run.params>${profiler.args} -classpath %classpath ${packageClassName}</netbeans.run.params>
   </properties>
</action>

Two issues, first it runs the wrong goal.
It tries to run  <goal>nbm:run-ide</goal> not <goal>nbm:run-platform</goal>.

Second ${profiler.args} is missing the "-J" in front of each option.

If I change these two settings in a custom action I am then able to profile.
This would be fine except that ${profiler.args} is machine dependent so my nbactions.xml file will not work for anyone else.