So, you're using the charcoal as a heat source for the wood chips? Never thought of that, but I've never had a grill with a rotiss burner. When I had a rotiss, I used the main burners. Never ocxcured to me that they would lock out the other burners. Sounds like one of those "improvements" that make simple things like adding wood smoke more difficult. I guess if you get one of these things, you need to spring for the extra bucks to get a special smoker burner.
For my part, I have found that I don't miss the rotiss attachment at all. I believe that I can get the same or better results using other techniques.
If you don't like the food, have more wine