Merging Linear and Area takeoffs together in the same fashion as "box mode" can.

I typically do my asphalt takeoffs with both linear and area measurements. I would love to see the ability to merge the two (linear and area) just like we can with the box merge functionality (Link to Box), so that I only have one takeoff item that gives me the total area. I know that I can "group" them together, but I don't see that this ultimately gives me a total area calc. I could be missing something simple.....