When compiling a really huge schema, the generated method getRootElement() in the ObjectFactory class exceeds 65535 bytes.
The schema I was generating is the IFX version 1.4.0 (available from www.ifxforum.org).
Also, won't the hardcoded references to the implementation .class files result in them being loaded by the JVM when ObjectFactory is loaded? This will result in a long startup time (this was the reason the static initialization block was changed to use the .class names as Strings).