We have used it at a lot of kids tournaments. I'm not sure what you mean by combining weight classes. We use mostly Madison weights and make up our weight classes as we weigh in the kids. If you mean having an "A" and a "B" bracket at the same weight, and then having the winners of each bracket wrestle off afterward, the answer is "not directly". You would have to treat it like 2 tournaments, but people have done that. The nice thing about the program is that you can have up to 32-man brackets (double elimination) and up to 6-man round robins. You can have different bracket sizes in the same division. It's very flexible.
I hope that answered your question.