This should only be considered if there are no performance criteria for the dryliner to meet. 

If no performance is required from the Siniat Dryliner system then it can be stopped short of the soffit but there are a couple of points that must be carried out. The head track must still be installed over the dryliner channels and faced fixed through  with wafer head screws. This is to provide a fixing point for the plasterboards at its perimeter which is required at 300mm centres. You will also need to ensure that the last dry liner bracket is no more than 150mm from the top of each of the dryliner channels. 

General information on the Siniat Dryliner system can be found the website link here.