Measure your cold idle vacuum and set the transition point between cruise and idle flows 4-6 inches below that. With the unusually large overlap of that cam (large for that duration), I'd expect a lowish idle vacuum. Looking at the description of how to set this thing on the M/E Wagner site, it looks like you can just put in 1 of 2 springs to set this point; it looks like the screws are there to set the 2 different flow amounts.
Once that is sorted, then I'd be looking at the secondary throttle stop screw setting as another cause for this idle hunting. If too large, then the secondary progressives can be exposed and coming into the picture when they shouldn't. Are your main idle mixture screws really responsive to set idle smoothness when you adjust them, or do they not have much effect? If they are not very responsive, this is an indication that fuel is being fed in on the secondary side.
I'd doublecheck the carb float settings too. This whole deal can be a combination of things, so it can be a sequence of things to get settled down.
