Would we even want to try to mount toslink in the sled for repeated removal/insertion?

I think if you grind the male connector so it doesn't "click" into place, docking toslink should be fine. The difficult part is that I have no Eutronix board and no need to install one. Also, cutting the holes on the empeg itself (I think) can vary from installer to installer. So, wiring the SPDIF to the mic line may be a much better option.