Hi Mate,
Sorry for a late reply. There is no real way of putting Cam Position on the Z axis...unless you have an ADL as well...but, what you can do is put Cam Position on the Y axis and put you Throttle Position on the Z axis. This will be a little "interesting" to navigate but it will work.
Me, personally, I would be tuning the engine on the dyno at each cam position to see how much difference there is between positions. Realisitcally there is only going to be one cam position per load/rpm point that make maximum power so having a fuel/ignition map for a load/rpm point and for every cam position is going to be rarely of any value. Your cam position will be based on a fixed load/rpm so it should not be varying from this.
If you do a seperate tune for each cam position you will be able to compare each of them to work out how much benefit there will be. I would be interested in hearing your thinking behind what you want to do.....maybe it's something I have not thought of before.