When retooling the workflow or logic, I typically freeze the node that is creating the “thing” or in your case, the rev clouds. Only when you get the logic how you want it would you unfreeze the node.
I just realized, when you mention temporary generic model, is it the temporary Revit preview that is showing?
The deletion sounds like an element binding issue. How are you envisioning running this workflow? Will it be just you, or will you give it to your coworkers to run as well? I believe the Dynamo player can handle element binding and ensure that when you rerun the workflow, it won’t delete the previous effort. Here is a forum post about element binding, and I know there are a lot of other posts regarding this issue.