You should be able to see your cannon balls on the graph anyway, so you will know how far off the bottom they are running. You can do the same thing only without a stacker. Use the trolling app and find a setting that will run 10 feet down at a certain distance back and then run your cannon-balls 12 feet off the bottom. That way, you don't risk snagging a cannon-ball on the bottom and the baits are running below the cannon-balls, which may spook the fish as they come through.

Guys use a modified version of this for steelhead that some call the SWR "Secret Weapon Rig". They run 5 colors of lead-core off the cannon-ball with a spoon attached. That gets the spoon further away from the boat, gets it below the cannon ball and the lead-core has a dampening effect on big waves, making the presentation more natural in rough water. The same would work with shallow diving body baits for walleyes. Cheers!