In the docs it shows this image:
But I can’t see use library path checkbox.
This is a massive problem because I lose all my bakes every time I save, and there is no way of appending the data. The reason is blender chooses to save the dynamic paint cache under the blend file name which makes the directory change every time I save with a new file name.
Help would be greatly appreciated, thanks 
Here is what I see under dynamic paints physics properties.
