Here is an attempt at merging this into a single DH. I don’t have blinds so I have not tested the blinds portion.
In settings for the device (gear icon), you select shades or blinds. This has normalized the commands switch (on open, off closed) and for WindowShade.
https://github.com/imnotbob/SmartThings-1/blob/Develop/somfy_shades.groovy