The SD's parameter modification can be save to use it later as new style.

Click on the current style name, and chose "Create Preset" option at the window 's bottom and name it.
After that, the new style can be select from the list.

To create a new style faster, it is better to work on a little image so the preview mode and tests render will be quicker.

Generally a rendered image seems the same picture, whatever it renders at different size or resize down from a greatest one. That is not true with SD. 
Example:
Both images below use the "SketchDefault" style and created from the same original photography.
The left one was rendered directly at 320x212 pixels. The right one was rendered 1278x849 pixels and resize at 25%.