Not possible, period. Dont have the source right now, but SE already stated once, that this isnt possible due the complicated system behind the que'ing. If you que up with multiple class, the DF basically couldnt make any teams. For example you que CT as heal and Coil as tank - The DF will register that and que you up for both. Once you get invite for, lets say Coil, the ones waiting for CT would lose the heal, you have registered. Waiting times would increase drastically. Its a nice idea, ik. But definitely not doable.