RB will use the 8 outs if the device allows it. I do it often with 1010lt.

Trick is to enable the ports in the audio options area by highliting them, then you can right click each track and tell it which port (output) you want it sent out on. Make sure your main output stays at the top as the default, then you can assign tracks to other outputs individually.

You can even set up subgroups inside RB (bottom right of mixer panel) and group instruments to certain outputs. I've done drums this way; send all 8 drum mics to the stereo subgroup so once I have volume/panning of individual drums balanced I can use the subgroup to balance the volume of the whole set to the rest of the mix without having to reset everything..

Make your sound your own!
.. I do not work here, but the benefits are still awesome