I completely understand your concerns, but I question the need to run optical out of the DTV receiver. I am an audiophile, like you, and I run optical audio out of my TV to the audio receiver (Pioneer) directly. Optical audio is known for causing delays, and I have experienced delays when using optical that are not experienced when running optical out of the TV directly to the receiver. It's not reasonable for DTV to be able to accomodate every single receiver in the world, especially an obscure brand like Rotel (don't they make spaghetti sauce?).
Try reconfiguring your setup and not running optical out of the receiver.