AppleTalk has profound problems determining whether to use ethernet or LocalTalk. In ye olde days, AppleTalk had to use the Printer port and there was no option to change it. AppleTalk cannot even look at a multi serial port board.
In ye olde days, third party manufacturers made boards with multiple serial ports in order to connect Mac IIs running A/UX to serial terminals. It would be interesting for someone running A/UX 1.x to test your card.