No, not officially, but one of my favorites is Blueberry Cheesecake, and another favorite is Raspberry/Cheesecake/Brandy, and when I switch back and forth between those two I just start adding drops of one into the cartridge that already contains the other, and the transition tastes fine to me. But to my taste buds it doesn't have any kind of sourness, so I don't think you'll get a sweet-sour flavor that way.
Some mixture with lemon or lime might do it, like maybe cherry/lemonade. I tried Orange/Lime before, which some people like, but it was too limey for me so I didn't finish that bottle. Orange/Lemon might work.