A local roaster/cafe was running a house blend and a second variable blend through a Mini Mazzer for a few months. Unfortunately the Mazzer was on loan and now that it has gone back, replacing it hasnt been a priority. I really enjoyed being able to compare and contrast different blends or SOs at the same time.
Probably a reasonably expensive hassle for all but the most dedicated cafes.
Dropping in to see Corey Diamond at Core Espresso might be worth your while.