That’s fine… but you will need a library of classes that they both share. The classes that they send back and forth must be the exact same .class files or you will pull all of your hair out.
That line is no longer needed on clients. Your tests must be using old spider monkey code.
If you want to look at another example you can try this:
It does some extra ES related stuff but that shouldn’t matter to prove that things work without message registration on the client.
If the client is requiring that then you are running old spidermonkey code… like pre 3.1 alpha 1.