"For a mailbox requiring transfer capabilities, it is possible to loop a spare extension port to a spare CO line port and assign a personal operator to the spare extension and then assign a spare auto attendant to the CO line to provide transfer capabilities."
Have you actually done this and got it to work? I tried this on an installation a few months ago, and when the auto attendant flashes to do the centrex transfer, it is flashing on the extension, drawing intercom dial tone. So then I tried to set the centrex transfer number to #03*5551212 on the theory that the #03 on the intercom dial tone would do another flash out to the CO line, the * is a 1.5 second pause, and then the telephone number. Almost works, except the VS mail does one more flash automatically at the end of the number (I guess to set it up as a 3-way call), then disconnects. Needless to say, it didn't work for me.