The new boards and chips have arrived, and over 200 solder joints later, the Teensy and 53c94 are talking, and menu buttons are working. Now to finish separating the 5380 code from the target service code the rest of the way, and write the 53c94 driver. There is one downside to the 53c94 that I didn't notice before, it only can listen on one device ID at a time. It can still do multiple LUNs per device, but this means most of the modes are mutually exclusive for older software where LUNs are not supported. So you could emulate a harddisk, cdrom, ethernet, or graphics adapter, but not any of them at the same time on a m68k mac. The 5380 is slower, but more versatile on this one point.
On another note, the SuperMac SuperView arrived, and I was able to get it working with the Quadra 630 in my collection (albeit very poorly, as it causes issues with the native graphics). I hope to reverse engineer that protocol soon and start work on the pi Zero software.