I'm about to tackle an identical problem. I am in the architecture phase. Did this every get resolved or am I barking up the wrong tree.
My hope was to treat a cloud connector like a Decision Step. I had contemplated moving them to another step in the API but I doubt that is practical, though I am pursuing this still.
I was just going to have the connector delete the members from the Campaign as a plan B design. If you were able to do this then I have my back up plan and can rest easy.
Any help would be greatly appreciated.
Scott