Config
In saves\YourWorld\serverconfig there is a file called beautify-server.toml. This is the only config you need to edit.
Obviously, you will have to navigate to your World Folder, not "YourWorld".
When you open the file with any Text Editor (Windows' "Editor" is enough) it should look something like this:
Do not edit any lines with a "#" in front. What you need to edit is searchRadius and opensFromRoot
The searchRadius determines how many Blocks away from the root block will be opened or closed. A searchRadius of 6 would search 3 blocks to the right and left and 6 Blocks down.
If opensFromRoot is true, the Mod will search for the Blind that is the topmost Blind of the Blind that has been clicked.
For example, if you click the Blinds at that Block, they will close from the top like this:
