I just received a response to my question from Bryston's Chris Rice. He said I could post his response:
"Yes, with new enough firmware you can connect either a drive or USB DAC to any of the BDP’s USB ports. Any of the USB ports should work, however for aesthetics you’ll likely want to use one of the rear USB ports. This being a BDP-1 you’ll want to reserve the rear lower USB port for a USB hard drive if you intend to use the BDP with a bus powered USB hard drive. I can’t say I can guarantee it, but it would be pretty poor DAC design if plugging the DAC into something that follows the USB spec to the letter where to break it. I don’t believe plugging it in will cause the DAC to malfunction. It should support whatever the USB DAC supports."
Thank You Chris and Bryston