You can elevate the chainstays by increasing the E value in the chainstay dialog box. If you only want to elevate one stay, you can check the Asymmetric box at the top of the dialog box. Although you can uncheck the Include checkbox at the top of the chainstay dialog box to eliminate both chainstays, there is no official way to exclude only one. However, if you set VR, VF, HR and HF to 0 you can make one of the asymmetric stays disappear.