Walkera devo 12s setup

I have recently bought a Devo 12s and put Deviation software on it. I am trying to set up a Walkera 4G3, which I know is not a supported model and also not a very good model. I can not find how to set up gyro gain on the radio and thus tail control is impossible. Can any one help? Is it even possible to control the gyro on this model from the radio? It always was a rubbish model, should I give up and just buy a Super CP/ 120D02s etc?