Otay! I think I've figured out how I wish to word my reply. Although there are several schools of thought here...this will work for you with the sugar.
I would like to believe that smoking would be the most tried and true method yet I have done the direct method in the past. But instead of using the grill racks I've opted for the rotiserie with the burners or the infra-red burnerfor more of an indirect method. My last char-grill (Weber Genesis) didn't have the infra-red burner so I used the bottom burners. Took abit of adjustment to get it right. Our current(JennAir) has the infra-red burner and it works about the same but with less tweeking and you don't have to refill the water pan as often.
Slowwwww over low heat is the the most effective form of cooking so you don't end up with the knots that have been mentioned. Nothin worse that trying to chew a rib that hasn't cooked the right way.
Since you've chosen the direct method... I believe this is much easier with the rotiserie attachment. Flare-ups can be greatly reduced since you could put a water pan under the meats and you'll get a very nice crust from the rub/seasoning/natural juices that roll on the meat. Plus you have the ability to baste the meat with your sauce without fear of having in all stick to the grates. No matter what, between the natural sugars contained in the food and the added sugar, you will get a certain amount of carmalization but it should not be like a charred piece of carbon.
Hope you have the rotisserie attachment for your char-grill and can give this a shot. I believe you'll be happier with the results. Now you can use the brown-sugar.
Now back to the peanut-gallery for me.