Very good ideas and suggestions. I missed the USB solution.

First of all, I agree that USB2 is preferred over USB or firewire. It is faster. It is fair to say that most computers have USB. But there are two problems:

1) ONLY newer computers have USB2.0... (made this year or so)
2) I recommend disabling USB in any DAW. So mine is disabled. This is very controversial and I think there is a work around for it.

Modular approach is basically buying separate SCSI (OR USB2 if it was available on the keyboard) external standalone cd-writer. In fact, we had this option with the WK/SK arranger. It came with scsi option. But I never purchased it. This standalone CD-writer must have a 700MEG internal buffer to receive data before burning it to CD. But I think as the original post said, you lose practical convenience and that is the reason I never purchased that SCSI option (I also hated the installation).