Yes, you can overwrite existing profiles. You will have to move the material to the device in the 'Material Tab' and then you can overwrite the T1 profiles using the 316L for the material & set the pre-heat, etc. where you want it...In the materials tab, click on the 316L .csv on the 'Available Materials' side, and the click the little arrow to send it to the "Materials On Device' side, then you can build your profiles using the 316L