In layer panel one can only pick a blending mode from the list one mode at a time. It is a common practice to search for the best blending mode for a particular layer, traversing through the list with a UP and DOWN arrows on the keyboard or focusing on the list and using a mouse wheel. This is used a lot in photobashing and applying textures to the painting.
This is also how it's done in Photoshop and I think will be a quick win for the Paintstorm Studio.
To make it even better I would make those up and down icons on the dropdown list component react to clicks, selecting a previous or next blending mode. This way it would be easy to traverse list elements with a pen.
