A properly configured pom to keep as3Metadata, durring the optimization step, it strips out the tags.
After some debugging, it turns out that the optimizer doesn't receive the configuration, so it uses default values for keepAs3Metadata
Have a look at org.servebox.flex.mojo.MakeSWFMojo / compile()
123: WebTierAPI.optimize(in, out);
doesn't get an instance of the configuration.. should be something like
WebTierAPI.optimize(in, out, configuration);
If required, I can provide a test flex project to debug this.