Additional info: We used to run the following script to get Subdescription 1 filled with the size, but that was with 1.3, maybe because Matrix Detail1 is now called Dimension1 it's not working? I know we had to change some other scripts because of name changes from 1.3 to 2.0. Here's the script...
-- 2.2. Move Matrix Detail1 to SubDescription1 (Only if SubDescription1 is blank, otherwise leave it as is - NOTE - if you are changing a size that's already existing, you need to physically change the size in the parent item and in the Subdescription1):
UPDATE Item SET Item.SubDescription1 = b.Detail1 FROM Item LEFT JOIN (SELECT Itemid, ItemClassID, Detail1, Detail2, Detail3 FROM ItemClassComponent LEFT JOIN ItemClass ON ItemClassComponent.ItemClassID = ItemClass.ID WHERE ClassType = 0) b ON Item.ID = b.ItemID LEFT JOIN ItemClass ON b.ItemClassID = ItemClass.ID WHERE b.Detail1 IS NOT NULL AND Item.SubDescription1 IS NULL