Adding a shader to a map layer scales the entire watch face down and looks broken.
Steps to reproduce:
1. Create a new watch face with a map layer.
2. Resize the layer so that it is cropped (I did this on a 360 face, so it crops the entire map to a circle and the map fills the screen.
3. Add a shader such as HSV or RGB to the map layer.
4. Push the watch face to your watch. It will be very broken looking.
Images here: https://plus.google.com/+SamGarfield1/posts/MEMMEhhFe1C