List (and /or Remove) Unused Columns in Data Model
User built a report with a "Select * ..." query that imported 100's of columns. He used a few dozen columns, spread over many pages. It would be good to have a way to identify all the columns not used anywhere (M, DAX or visualizations) so we can clean up the data model. Idea: gray out unused columns in Power Query, or in Relationships, or Data would help. Better, extend to a list so we can uncheck columns we might use and a button to bulk delete all the checked columns.