I’ve read somewhere that some people could not get lightscribe support to work after cross flashing to a 4166B. But to get lightscribe to work, you apparently need to install an extra piece of software called a lightscribe engine or something like that. If you don’t install that, even if your writer is lightscribe capable, Nero will claim otherwise. I cannot recall where I read that, but I am not really the expert on this.
Have a look at this thread :
italianjob who posts there is probably much better suited to answering your questions about cross flashing the GWA-4164.