You should be able to do the 4 servo wing on a US. I am flying my US60 with a 6XAS and it will do crow. I have the ailerons on channel 1 & 6 and the flaps on a Y on the gear channel 5. I use a mix to add some down elevator with the flaps and the airbrake mix pops the ailerons up and adds a little more down elevator. To deploy crow I have to flip the gear switch to drop the flpas and flip the airbrake switch. The only thing I can't do is mix the flaps to the ailerons to create full span ailerons because of only 6 channels. I might be wrong but it seems I only need one more channel to do it. I do plan to buy a 9C for this and other models.