This is the firebox: http://www.presonus.com/products/FireBox

I think if I understand you correctly, if I use SPDIF, then everything audio related can be handled through the Firebox interface. I'd still have to run a USB to the PC, it just wouldn't be for audio purposes, but it'd still work to control my interface?

The only issue with that is running another cable, which I was trying to avoid. But it's definitely a solid backup option if the ASIO4ALL doesn't solve my issue.