Sometimes, I cannot get Refscope to select the item for me - i.e. I can console select a "WTF Missing Mesh" with mouse, but not through Refscope.
Also, FormIDFinder allowed me to check an item in inventory without dropping it. Never figured out how to do that in RefScope either.
Have you tried just clicking to select Refscope as a spell? You don't need to cast it. Anything after that that your mouse is on should light up, and clicking should bring up the data. Ought to work with inventory, too, but I honestly don't remember trying that aspect of it lately.