And worst case, this isn't a fatal issue for a prototype. Having half the ports only run in 100baseTX mode, or even not work at all, would surely be annoying. But it wouldn't prevent me from using the board as a development platform for the full scale 24 port switch, which was the real goal.
But I'd like to make it fully functional if I can.
Not happening tonight, though. I've got too much else on my plate with time constraints.