I have that and use it for many things, but haven’t used it for blueberries. If you do, the trick would be to fill the shoot, apply pressure to the plunger and then pulse it. That will give you the largest cut pieces, albeit unevenly cut. Love mine. Use it for sauerkraut, and cutting garlic to dry (similar application) to make powder.
There must be an attachment for that. Doing blueberries with my mandolin would seem almost as time consuming than rough cutting on a cutting board with a large knife and would seem more dangerous than…well…grafting. 
My office manager has one and they are very noisey, so if you are considering one you might want to ask about the decibel levels. Would probably still have to cut them up. Her husband freeze dried some persimmons I gave them and truly they were better than any candy (well, except chocolate).