Hovering over an item in the Hub Upgrade window should highlight the same item in your inventory to make it easy to find. Items need to be drag-dropped or shift-clicked to move them from your inventory to the Hub Upgrade window. Right now I need to hover over the item in the upgrade window to see the tooltip for what that item is, and then slowly hover over items in my inventory to find the right item. I don't see any downside to making hovering over an item in a crafting recipe or the hub upgrade window light up that same item in your inventory to make it easier to find.
In the same vein, it would be nice be able to configure the delay before a hover tooltip becomes visible. Right now the delay is pretty brutal, it's like a half second, and I'd like for it to be immediate.