colin,
It WILL work. Add the routing commands to the IR database and adjust the scenario's commands in the webadmin. The other method is too ugly to offer here.
I have an RT8 and it works great, but since you need to feed it the correct code to select the output first, it wouldn't really work in this situation. This is especially important when more than one device is being controlled at the same time. Since I don't think rndinokc is already using a zoned ir system, control is probably being done either on-screen or on a mobile/web orbiter. Either way, the hybrid has no way of knowing what routing code to send to the RT8 to begin with since it can only be assigned to a single room. Plus, an RT8 runs $150, the RC68+ programmer is another $100, so it's a $250 investment for a workaround that is kind of a pain.
Get the other MD's. It's cleaner and will give you so much more functionality than an independent hybrid.
:Matt