Just a point for people to be aware of.
If you are using clamp/expand with tiles be aware that it will only work within the context of the tile. This means that the expansion range that will be used will be the range of heights within the tile, not the range across the whole extent.
This I consider reasonable, even though it screws me. I will just have to get my combiners right! 
I guess any device that comes with the warning ! will also produce problems in tiled builds.
Clamp should only be problematic when used with the normalize option set. As an equivalent alternative, you can add another clamp before and press Find Extends in it’s settings. 